When working in a multi-floor office, taking a shit on a floor that isn't yours without anyone knowing it, and leaving it there.
Kyle: Gotta go drop a deuce
McMillan: Go ghosting in HR down two floors. That'll show the bastards...
Chad: Just got back from the can - someone took a gigantic shit on our floor and didn't flush!
Ron: WE'VE BEEN GHOSTED!