According to the paranormal research team at LiveSciFi.tv, no the “Paranormal Activity” series is not based on a true story.
Oren Peli said during an interview with the Pittsburgh Post-Gazette that moving to a home in San Diego inspired the film.
“I never lived in a single detached family home,” he said, so he was conscious of every noise at night, particularly of the house settling and items slipping from shelves. That led to thinking how a video camera might document the source of the sounds, which led to the movie.
Still, tons of credit and all the kudos in the world to Oren for making a legit indie hit!