This a pressure plate switch to set off these cheap little skull things from Wal mart. they were made to be path markers and came with spikes to stick into the ground but I wanted to use them as porch decorations. I extended the wires with some old speaker wire so i could hang them around, and used the "try me" switch that was in the cardboard box as the switch to activate them. It worked well and survived the 70-100 kids we get every year.
Step 1: Just a small scrap of particle board