All you need is a bandaid wrapper. (You should have plenty of those will all the skinned knees around your home.)
- Put the bandaid wrapper back together after you've taken out the bandaid. (most bandaid wrappers are two pieces that pull apart and have a sticky film on the sides that face each other. you need this kind of bandaid wrapper.)
- Go into a completely dark closet or room.
- Pull the wrapper apart really fast.
- You'll see a small bright line of blue light.