Williams experienced a series of frights in her temporary home during production on the first version of Poltergeist — she said in her AMA that the picture on her apartment wall kept shifting while she left to shoot the movie, but she later decided it was her own fault for slamming the front door. That's still just conjecture, but, hey, whatever helps her sleep at night.
Author James Kahn, who was novelizing the movie, also experienced a case of the heebie-jeebies when a lightning bolt struck his building as he was finishing up the project and blew the facing of his air-conditioning unit blew across the room and struck him in the back. After that, the lights came back on and his video games "started playing themselves." We wonder what he thinks of games that they play themselves nowadays being a beloved feature, rather than something out of a freaky nerd nightmare.
Director Gil Kenan had perhaps the biggest case of shivers surrounding Poltergeist, while filming the 2015 remake. In his Reddit AMA, he wrote that the house he rented for production was the site of some minor inexplicable phenomena, like lights flickering on and off for no reason, and other equipment only working in certain portions of the property. "I used a lot of aerial drone photography in the film, and the drone-pilots were never able to lock in the GPS signal in this field. We would have to move 10 feet away to launch the craft," he added. But it was his own personal abode that had him utterly freaked:
"The house that I rented during filming was straight-up legit haunted by a female spirit dressed in black," he wrote. "And I became aware of her within the first few days of staying in the house. And only after I left did I receive a call from the previous owner, who had moved back in, who was terrified by the goings on in the house, and wanted to see if I had experienced any of it … she definitely was there. It didn't follow me back to Los Angeles, but it followed me from set back to where I was sleeping during filming."
If that story was just some elaborate marketing ploy, it worked, because there are plenty of people who fully believe there was something truly otherworldly going on with the Poltergeist movies.