I used to believe that a light bulb would light up if I put it in my mouth. I guess this belief started when on Small Wonder (I forget what episode) Ted Lawson used Vicki the Robot to test a light bulb by putting it in her/its mouth.
A childhood belief about special powers

others believed things like this
- In "God Bless America" I thought it was "With the light from a bulb" instead of "from above."— Carol
- I used to believe that I could make a laser by putting more batteries in a flash light.— Tyler
- I used to believe there was a newsreader inside the radio where the light was!!— Christine
- Whenever I went to bed, I use to believe that when i flicked my light on and off I would signal aliens. — Laura.
- I used to believe that God was the light rays shining through the clouds.— Lynn
- I used to think light sabers were called life savers.— alison