The cast and crew of new thriller Insight were left spooked during night shoots while filming at an abandoned hospital, which has been listed as one of the most haunted sites in Los Angeles.
Linda Vista Community Hospital in Boyle Heights, where the pilot for E.R. was shot, has been shuttered for 20 years - following a string of lawsuits connected to the place's unexpectedly high death rates.
It has been the site of several televised paranormal investigations and was placed on the National Register of Historic Places in 2006.
The moviemaker says, "It was extremely creepy and scary, which really helped the feel of the movie - because it's a supernatural thriller. It was challenging at times.
"I can't say anyone saw any ghosts but you could feel death in that place. There was actually one time I lost my producer for two hours - he wandered off and got lost. We worried that something had happened to him.
"He was terrified because the electricity would go on and off and the lights would flicker."
But Gabai admits he had more than ghosts and ghouls to worry about while making the film - he was on such a tight budget he agreed to share the location with another production.
He tells WENN, "There was another film shooting simultaneously so we had to observe tight schedules, as did the other director, so our projects didn't interfere. Can you imagine shooting a tense scene and hearing 'Action' from another part of the hospital?"
But Gabai brought the film in under budget in just 15 days, despite the obstacles.