Not sure if it's my only case, but my memory sucks, so I'll stick with it. When I was about 5, I was in that dangerous state between stupid and smart: I absorbed scientific facts like a sponge and understood them, but I didn't have any common sense to go with it. I was also addicted to computers pretty much. So, one day, the computer's unplugged because we had to move something in the room and then move the computer desk back. Sadly, it wasn't plugged in again. It was impossible for someone my size to move it and the angle was too hard to plug it back into it's regular slot. So I look about the room and see the closet, which has quite a few metal coat hangers in it. Struck with "inspiration", I knew even then that metal conducted electricity well, so I took the plug and started tying the coat hangers to it, with the intention of eventually plugging the end of the chain into a wall socket.
Thankfully, my dad walked in on me a hanger or two before I had finished (thank God I started on the plug side, huh?) I'd finished my masterpiece, but yeah. Near death experience (without the trauma anyway).