I'm trying to create a flickering effect in the bathroom of my haunted house. My goal is to use a greenish light and have it flicker occasionally. I'm going for a Saw-ish feel to it, making people as uncomfortable as possible while in the bathroom. In the tub, there will be a dead body and a toaster. REDRUM will be written on the wall across from the mirror.

Any tips would be a HUGE HELP!!!

Also, any tips for cheap and border-pushing effects is helpful. I want to make people want to vomit a little. This isn't a kiddie-party!