How to Create a Ghost Illusion for a Haunted House - One of the scariest, and most impressive, effects at haunted houses are ghost illusions, in which spectral bodies or heads appear to float right in front of you. While this trick, also known as Pepper's Ghost, is the secret behind the ghosts at Disney's Haunted Mansion, it is actually very easy to create yourself. The illusion can be done in a front window to spook people who come to the door, or it can haunt any room of your house.