Slide one end of each alligator clip into the holes of the pumpkins and pull them tight against the bottom. Each year, our library hosts a trunk and treat event. My role is to provide an interactive decoration. I use the Makey Makey, my favorite invention tool, for these decorations. The first year, I created the decoration described in this Instructable: Screaming Pumpkins. Connect the ground alligator clip to the end of the knife with aluminum foil. Wrap the alligator clip cord with aluminum foil to disguise it. The knife completes the circuit so should be metal or wrapped in foil. My decoration was family friendly so I used a table knife. Cut pieces of double-sided carpet tape over each marked circle on the top of the box. Make a hole in the center of each circle, through the tape and the top of the box. It should be about 1/4 inch wide, wide enough for an alligator clip to fit through.

Pumpkin Scream : 7 Steps (with Pictures) - Instructables Pumpkin Scream : 7 Steps (with Pictures) - Instructables

Remove the handles from your pumpkins if they have them. Use a tool--I used a small screwdriver--to make a hole in the bottom of each pumpkin. It should be about 1/4 inch wide, large enough for an alligator clip to slide inside the pumpkin. The illusion works when you can't see the Makey Makey and the device. Place your box on a table covered by tablecloths. String the USB cord behind the box and under the table. Place the device under the tablecloth.