I didn't really do much in high school, but I witnessed these: My junior year one of the seniors took a fire extinguisher and sprayed it in someones face, and last year someone hit a breaker box in the hall just right, so it would open and started messing with the switches. A teacher across the hall was apparently doing some important work and came into the hall to freak out. They got the superintendent to come herd everyone who was in that area down to the end of the hall to try to figure out who did it, but of course nobody told.