Speaking of Stephen King....
Some of his subject matter might provide ideas - I've had dreams (when I've had stressful days, I guess) about images I formed in my mind after reading Tommyknockers:
Get some of those 5-gallon plastic water bottles, you could cut them and fill them with weird things (dare I say dolls?) then super glue them, attach some rubber tubing and have someone design a way to make them "glow" from time to time; make like a mad scientists lab.
Or how about Needful Things? Any of King's stories that have a good image of a physical reality of some sort that can be reproduced might give you ideas. If you like, I'll post more.
How about using X-files material?
How about doing something like the alien autopsy and have someone in an alien costume on the table and have them sit up when people come by? Or maybe use some ideas from the Simpsons halloween specials.