You and a few friends decide to make the evening a little extra spooky by pulling out a Ouija board and trying to “contact the dead.” Your hands move as the planchette glides across the board, slowly spelling out… your name! You cry out in fright, but your friends burst out laughing: it was all just a trick. You begin laughing too, red-faced for having fallen for it — after all, only kids believe in ghosts… right?

Believe it or not, two of history’s brightest minds were actually dedicated ghost hunters, convinced of the presence of specters within our physical world. To that end, these men built tools to contact such spirits — and the messages that returned from the other side are enough to make anyone’s hair stand on end.

Considered the fathers of modern technology, Thomas Edison and Nikola Tesla both had competitive streaks to match their towering intellects — especially when it came to stacking up against one another.

The New York Times

The pair first crossed paths when Tesla emigrated to New York to work for the Continental Edison Company. He quickly rose through the ranks as an engineer, though Edison didn’t see the promise in the young man that many of his colleagues did.

Following a joke offer of $50,000 from Edison for 24 of his designs, Tesla quit ConEd after just six months on the job. He set out to create a manufacturing and utility company of his own, and in April 1887, the Tesla Electric Company was born.

Tesla’s reputation as a brilliant inventor only continued to grow, eventually drawing the attention of his former employer. Edison was far more established within the scientific community at this point, though there was no denying the growing tensions between the two heavyweights.

Their rivalry came to a head with the “War of Currents,” which saw Tesla’s revolutionary alternating current pitted against Edison’s direct current for supremacy in the expanding age of electricity. Tesla won out in the end, a victory that would haunt Edison for the rest of his days.

Avalon Library

The two inventors continued to clash in the years that followed, though around the turn of the 20th century, Tesla began dabbling in a field unfamiliar to Edison. Instead of currents, Tesla sought to prove the existence of another unseen force: ghosts.

After building a crystal radio powered by electromagnetic waves, Telsa began picking up unusual readings within his lab. Translated into audio, these readings were so unnerving that the inventor couldn’t help but chock their explanation up to ghosts.

“My first observations positively terrified me,” Tesla wrote in his diary, “as there was present in them something mysterious, not to say supernatural, and I was alone in my laboratory at night.”

Years later, Tesla ran a similar set of tests, though now with a more advanced model of his first radio. This time, the strange sounds were unmistakable: they were voices.

“The sounds I am listening to every night at first appear to be human voices conversing back and forth in a language I cannot understand,” he wrote. “I find it difficult to imagine that I am actually hearing real voices from people not of this planet.”

Reader’s Digest

Before Tesla could deduce the source of the voices, however, Edison caught wind of his rival’s attempts to converse with the dead. Despite being an agnostic and critic of the paranormal, Edison became fascinated with the concept of a world beyond our own and set to work on his own invention.

“I have been at work for some time building an apparatus to see if it is possible for personalities which have left this Earth to communicate with us,” Edison told American Magazine in 1920. This device would come to be known as the “spirit phone.”

PBS

Edison’s invention was entirely rooted in science, specifically Albert Einstein’s theories of quantum entanglement and special relativity. He posited that if it was possible to convert mass to energy, then maybe “ghosts” were just the coherent energies of the deceased interacting with the physical world.

With his “spirit phone” in hand, Edison decided to put his hypothesis to the test. He invited a number of scientists and spiritual mediums to his lab where he presented them with a projector-like machine shining a thin beam of light onto a photoelectric cell.

According to Edison, the photoelectric cell was capable of detecting the presence of objects moving through the beam — even those he and his guests couldn’t see. If a supernatural force were to manifest in the room, the cell would surely let them know.

Yet as the hours passed, the meter on Edison’s machine never even budged. He continued tinkering with the “spirit phone” throughout the 1920s, though the genius inventor was never able to make contact with the dead before he himself passed in 1931.

So, what were those strange “voices” Tesla had heard through his radio decades earlier? As it turns out, there was a completely scientific explanation for the unusual phenomenon he was experiencing.

Unbeknownst to Tesla, his radio was actually picking up low frequency radio signals given off by household electronics, distant electrical storms, and even the room’s lighting. When converted into audio, these signals sound almost identical to low, rumbling voices.

Despite their failure to reach out to the other side, one of these inventors actually tried to contact us from the dead back in 1940. A group of researchers claimed that Thomas Edison himself reached out during a seance with instructions on how to build a working “spirit phone.”

Unfortunately, the machine they built was no more successful at contacting spirits than Edison’s was. And so, the existence of ghosts has more or less been written off — at least, by some.

According to a Gallup poll, 37 percent of Americans believe ghosts inhabit and haunt houses. Other people claim to be skeptics, but with the booming tourism industry surrounding spooky spaces, and highly watched programs investigating the paranormal, it’s clear: people believe in ghosts.

Trolley Tours

One thing we can be sure of is that those people crying haunted house are experiencing some very real symptoms. Temperature changes, inexplicable shadows, pounding hearts — something triggers these physical reactions, but what?

Travel Channel

On a Halloween episode of the popular NPR program This American Life, they retold an ominous story documented in the American Journal of Ophthalmology. A medical journal doesn’t usually scream “scary story,” but this entry was goosebump-inducing.

Armchair Expert

The year was 1921. Mrs. H — that’s the only hint at her identity — and her family moved into a great old house on November 15th of that year. Fairly quickly, the family collectively felt the effects of an otherworldly presence lurking in their new home.

Shane Gorski / Flickr

All the components of a sinister-seeming property? This house had them. In its state of age and disrepair, electricity hadn’t been wired yet. The only source of light was the glimmer of eerie gas lamps. Carpet softened footsteps pacing the halls, leaving an overwhelming sense of total quiet.

Flickr

Mrs. H’s physician detailed her account of the growing sense of unease living in the house: “Mr. H and I had not been in the house more than a couple of days when we felt very depressed.” That sense of dread worsened once strange things began happening.

Flickr

Footsteps were heard pacing empty bedrooms, for example. After everyone was tucked into bed, the noises started — loud booming scrapes and thuds. All the members of the H family quaked in their covers, squeezing their eyes shut at the bloodcurdling wails.

Carla Smith / Flickr

Mrs. H recalled her 4-year-old son questioning who kept calling out his name and pounding on the walls when no one was nearby. Parents and children felt powerless as their beds shook without any visible cause. Even all their plants suddenly died. Mrs. H’s fear for her family’s safety was reaching its peak.

“One night I woke up and saw, sitting on the foot of my bed, a man and a woman. The woman was young, dark and slight and wore a large picture hat. I was paralyzed and could not move,” Mrs. H explained to her doctor. The family, weak and energy depleted, were certain spirits were to blame.

Alexis Snyder / Flickr

In January, after months of fear and torment, Mr. H’s brother visited the family in the home, and they filled him in on the ghostly goings-on. As he listened to their explanations, he thought all the different occurrences added up to only one possible conclusion.

Samara May Night / Flickr

The brother had read about another family plagued with similar problems, but they’d been suffering from gas poisoning. He urged them to get the house inspected immediately to assure they weren’t being driven mad by a preventable source before they summoned the Ghost Busters.

Of course, Mrs. H was ready to rid her family of this constant madness, even if it proved they’d been hoodwinked into blaming apparitions. They brought in professionals to check out the house.

Peter Wadsworth / Flickr

Low and behold, the furnace was leaking a dangerous amount of carbon monoxide into the home. For many, the gas is a vague low-priority threat that you trust some already installed detector to protect you from. But truly, the colorless, odorless gas can be fatal.

Flickr

In short, the gas prevents oxygen from circulating throughout the body and eventually stops it from reaching the brain. The gas, with an apt nickname of “the silent killer,” acts quickly, leading to disorientation and death. It’s the same reason running a car in a closed garage is incredibly dangerous.

NY Times

Albert Donnay, toxicologist and environmental health engineer, explained on the radio program, “Carbon monoxide poisoning can cause all manner of hallucinations… people often report that they hear noises in their ears, bells ringing, rushing sounds.”

Postcard Life Stories

Similar cases have cropped up in various news outlets. In 2005, NBC News reported a story of a woman scared stiff in the shower after supposedly seeing a specter. It turned out her recently installed water heater was leaking carbon monoxide.

Giphy

Routinely checking carbon monoxide detectors should be part of your yearly household responsibilities. It ensures safety from many dangers, not just the spooky. Plus, if you hear a bump in the night, you can rest assured you’re not poisoned into insanity, just dealing with an active haunting.

Good Houskeeping

Carbon monoxide can only account for a few documented counts of suspected paranormal activity. However, ghosts and even darker entities, pop up in homes new, old, and totally up to code. Sometimes the house, and the land it sits on hold onto the terrors of the past no matter what the homeowners try to do.

Philly

Stories of haunted houses usually stop short of anything truly frightening. Maybe the windows rattle or doors slam. In the case of former Pennsylvania councilman Bob Cranmer, however, the stories were a bit more unsettling…

Suzanne Stratford / Youtube

Just outside of Pittsburgh was a quaint home that Bob had been mesmerized by as a kid. After a long career in public service, he made an offer on the home. Strangely, it was accepted immediately, even though it was below asking price.

Suzanne Stratford / Youtube

Looking from the outside, you’d think Bob and his wife, Lisa, had pulled off quite the steal. With a well-kept lawn, fresh red paint, and a huge front porch, this seemed like the perfect place to settle down. But it would soon become the worst purchase Bob ever made…

20darkfall / Youtube

See, the house had a violent history. In the 1700s, a Native American tribe massacred a group of white settlers on the property. Then, in 1909, a disgruntled builder allegedly cursed the house. Yet these weren’t even the strangest parts of the house’s history.

Randy Jarosz / South Hills Record

Another theory was that an early 20th-century doctor allegedly rented a room in the house and performed over 100 then-illegal abortions. Put simply, some felt this house had a history of bad juju—and Bob and his family would eventually feel the brunt of it.

Suzanne Stratford / Youtube

From the moment Bob and his family stepped into their new home, something seemed off. As they did a walk-through of the home, the family lost track of one of their sons. Eventually, they found him crying on the staircase as if something horrific happened.

Ultimately, Bob and his family moved in but they could never quite get settled. For their first 10 years in the home, they experienced flickering lights and radio dials turning on by themselves. But then, in 2003, the intensity of the haunting escalated dramatically.

Suzanna Stratford / Youtube

In an interview with WJW Fox 8 News, Bob told the reporter: “We’d wake up on a regular basis with scratches and bite marks. This thing was out to hurt us.” What’s more, something ghostly would pound on the walls at night.

Suzanna Stratford / Youtube

Ryan Ruell, host of A&E’s Paranormal State, verified Bob’s claims. Ruell told People magazine that the house was his number one scariest encounter: metal crucifixes bent right before his eyes and a blood-like liquid dripped from the walls.

Suzanne Stratford / Youtube

Desperate to solve the ghost problem, Bob turned to an exorcist, who also felt something was strange about the home. Specifically, he was drawn to a single closet. “I [had a] really strong feeling there was something there,” demonologist and exorcist Adam Blai said.

Suzanna Stratford / Youtube

After he zeroed in on the closet, Adam cut through the plaster wall inside—a wall that had gone untouched since the house had been built. Inside, he found possessions from every person who had lived in the house since it was built. Still, the worst was yet to come.

Suzanna Stratford / Youtube

Included in the closet stash was a sketch of the home’s original owners from 1909, complete with some very cruel and almost evil things written about them on the back of it. This, Adam noted, was likely enough to invite the demon in, giving him power in the home.

Suzanna Stratford / Youtube

Eventually, when the strange happenings had reached critical mass, Bob claimed the demon revealed itself to his family. That part of the story unfolded in “The Blue Room,” so named due to the wallpaper inside. In Bob’s mind, it was the epicenter of the evil.

According to the book Bob eventually wrote documenting his experience, The Demon Of Brownsville, the demon manifested as a shadowy, foggy black figure that smelled like a must. And it drove his family mad.

Forward Boldly / Youtube

“My two sons were in a psychiatric hospital,” Bob told Fox 8 News. “My wife had spent several weeks in a psychiatric ward.” Bob and his family decided enough was enough. They needed to fight back—and fast.

Suzanne Stratford / Youtube

Bob fought the demon the only way he knew how: by staying up all night reading Bible verses. Still, he woke up each day with new scratches and bite marks. The family wore crosses too, but they would bend or end up broken on the other side of the room.

Suzanna Stratford / Youtube

Amazingly, around 2006, with the help of the exorcist—who performed any number of rituals over the course of two years—and Bob’s Bible reading, the demon supposedly fled the home. Finally, Bob was free.

Suzanna Stratford / Youtube

“If people don’t want to believe it… okay,” Bob said in his closing remarks to Fox 8 News. “But that doesn’t mean it isn’t true. It exists. That’s why I’m telling this story.” True or not, Bob’s experience far exceeds your normal house haunting story.

Suzanne Stratford / Youtube