Kennedy and I made a wire loop game, using some basic cheap electronics.
- 9v Battery
- Buzzer
- Old light switch
- LED
- Various wires
- Nuts and bolts
- Electrical tape
- Wire screw caps
- Cardboard box
The initial wiring and cutting of the box took more time than I figured and she started to lose interest until we got around to the top. We did this all on-the-fly, but there are plenty of tutorials (like one on Instructables) you can follow.
Nick's Blog 