Flickerling lights, spiders and a sheet that took on a life of its own?

TMZ.com reports American Idol contestants moved out of the Idol mansion on Monday night because the place appeared to be haunted.  The contestants were apparently freaked out by lights that began flickering and a spider infestation.  Several of them also reported seeing a sheet take on a life of its own and float down a hallway. Could this be a true haunting...  or a stunt to draw attention to the show?