How do you make a simple electric switch?

To make a simple electric switch, mount and wire a battery pack, copper bell wires and 3-volt flashlight bulb to a scrap piece of wood. Only use batteries for the power, as household electrical currents can cause serious injury.

To build a simple switch:

1. Collect the materials
This project requires: a battery power pack; a spring-tension clothespin; three 10-inch pieces of Number 22 insulated copper bell wire; small blocks of wood; a drywall nail; thumbtacks; a paper clip; and a 3-volt flashlight bulb.
2. Build the switch
Wind one of the wire ends around a thumbtack, and then hook a paperclip around the tack. Press the tack into a block of wood. Wind a wire end from the second wire around another thumbtack, and then press the tack into the wood. Then place a third thumbtack into the middle of the wood. This tack holds the paper clip in place.
3. Build the bulb holder
Nail the clothespin to a block of wood, and then use a thumbtack to place a loose wire from the switch into the wood directly under the clothespin. Wrap the other wire end around the bulb and clamp it in the clothespin. Use a thumbtack to attach the loose wire to the wood block.
4. Complete the circuit
Use the loose wire from the switch and attach its stripped end to the positive lead of the battery pack. Secure it with tape. Then take the loose wire from the bulb holder and attach its stripped end to the negative lead of the battery pack. Secure it with tape. Press down on the paper clip to close the circuit and light the bulb. Lift up the paper clip to open the circuit and turn off the bulb.