You can make a simple switch to use in your experiments.
Steps to be taken
1. Attach a piece of wire to each drawing pin. Push one drawing pin into one of the flat sides of the wood. Push the second drawing pin through the end loop of a paperclip and into the wood. The drawing pins should be about one centimetre apart.
2. Make sure the clip is held in place by one pin but can still turn around and touch the other pin. This is the switch.
3. To test the switch, connect the free end of one of the wires to one side of the battery. Connect the third wire to the other side of the battery and to the bulb holder.
4. Connect the free wire on the switch to the free screw on the bulb holder.
5. When you turn the paperclip round so that it is touching both drawing pins, the bulb will light up. If you turn the paperclip away from the second drawing pin, the bulb will stop shining.
A small block of soft wood, about 8 cm x 4 cm x 1 cm
A paperclip
Two drawing pins
Three pieces of plastic-coated wire, about 25 cm long, with bare ends