The worst thing I've ever done at bk is put mayo on a piece of cheese and slap it on the ceiling.
I had about 4 pieces up one time while in the kitchen, and decided to home, and the night closer was like "I'll take them down" and I guess he got bored, and put some more up, and later on he got high, forgot to take them down, and yeah, got written up, and got transfered to some other bk.