As you may know lights don’t turn on and off by themselves there is electricity and circuits involved. This is a picture of the inside of my flashlight. You can see the battery and LED, The switch is on the side but blocked by the battery. To set up my circuit I attached the positive side of the LED to one side of the switch. Next I attached the other side of the switch to the positive side of the battery. Lastly I connected the negative side of the battery and the negative side of the LED to make my circuit!