This illusion involves the group standing in an old freight elevator. All of the sudden the elevator starts shaking, and the elevator starts dropping at an incredible rate of speed. The elevator in actuality, goes nowhere, your depth perception makes you think it is falling. The brick walls of the elevator shaft that are visible through the slats in the sides of the elevator are actually on rollers going by at an incredible rate of speed. You'll swear you are plunging to the bottom of the elevator shaft.
The time I was in an illusion of this type, the elevator had been built like an old freight elevator with open slats on two of the sides. The construction of the continuous cloth rollers can be either the bricks painted on it or thin foam rubber brick shaped pieces glued onto the cloth rollers. Have the group enter one side of the elevator and exit the other thinking they have actually gone somewhere. The doors should slide up on rollers to allow entry and exit. The elevator could be propped onto heavy duty industrial springs to give it the shakes. Add a single, bare, low wattage bulb that has a tendency to flicker on and off as well as a realistic looking elevator control, and brother, you've got a heck of a ride.
The above "How-To" is an excerpt from Tim Harkleroad's "The Complete Haunted House Book" for more information about this and other great haunted house reference books go to MoonLighting Publication's website "Haunted House Books On-Line" at www.hauntedhousebooks.com. You can e-mail Tim at moonpub@aol.com