Hmm Ok taking the matter at hand.

For a haunted house I took a SCCA Club rally Race car(That I and friends helpped build) we took the tires off the wheels, put em on a "I" beam, flattened the non drive tires. The car would start up (driver inside) and would jump at the guests. the car would move 4 feet forward. and sparks would fly on the drive tires.

I made lights for an out door haunt out of tin cans cheap 24v lightbulbs from surplus store and laptop powersupplies(Free surplus) to drive em. (ultra low budget)

I just recently finished a Horn looking device the blows fire with electronic ignition using a flammable gas.

I also have made skeleton heads that would talk to the guests. using a plastic human skull kit. Motor and using a little easy circuit to drive audio to power. (that was in the late 80's)

-Gordo