One of the most basic electronic projects is a flashing light circuit, and is used to educate people in basic principles of electronics. If you have seen an indicator light that blinks on and off, like Christmas lights or an alarm indicator, you have seen a prime example of a flashing light circuit. Making your own flashing light circuit is both inexpensive not difficult.
Cut three pieces of wire, each about 4 inches long.
Strip 1/2 inch of insulation from each end of the wires.
Twist one wire to the positive lead of the battery pack and the other end of the wire to the positive end of the LED. The positive end of the LED will have the longer wire.
Twist one end of the second wire to the negative end of the battery pack. Twist the other end of this wire to one blinking Christmas light lead. It does not matter which lead of the Christmas light that you use.
Twist the last wire to the remaining blinking Christmas light lead, and to the negative lead of the LED light.
Insert both double AA batteries into the battery pack. You have now completed a simple flashing light circuit.