The supernatural drama began after contestants complained about bizarre flickering lights inside the house ... followed by a spooky spider infestation.
But the paranormal activity that sent the contestants over the edge happened last week -- when several wannabes claim they watched a bed sheet suddenly take on a life of its own and FLOAT down an empty hallway!!!
And as if the ghosts weren't enough, Sunday's torrential rains caused the roof to leak like a mutha.
Sources connected with the production tell us ... the contestants FREAKED OUT and demanded to move ... and "Idol" producers obliged.
We're told the gang is now safely holed up in an undisclosed location ... where the only blinding white objects are Ryan Seacrest's teeth.