I dropped a penny into the gap between the plug and the socket when I was a toddler. The sparks were FANTASTIC, and long lasting, like a sparkler shooting up the wall.

My dad tried to remove the penny with his metal pliers, my mom stopped him before he killed himself. She yanked the cord and it stopped.

We saved the penny for awhile, might still be somewhere. It burned two trenches in the penny, it almost made it all the way through.

Lessons were learned.