Story told to me by a buddy who served as nuke engineer on a submarine in the '80s.
Nuclear subs are high-maintenance machines in the extreme, and crews are constantly drilling in order to sharpen skills in the event of a disaster. Very professional, very necessary.
But there was this one junior officer who didn't enamor himself with the crew and generally made a nuisance of himself. To be friendless on a boat that won't surface for six months is not a good thing to be. He got on the bad side of folks very easily - he would walk into a room and randomly flip switches, probably to test crew proficiency, but he himself didn't know how to undo what he had done.
One night the nuke engineers are sitting in an engine control room monitoring the fuel flow, power output, etc. and they know the officer is on duty. Now, in SSBNs, all of the systems are redundant and functions can be re-routed to other displays. So, they decide to rig the panel closest to the doorway to go down if any of the switches are activated. Sure enough, the guy walks in, looks around, and flips a switch on that panel. The whole wall goes dark and the engineers start screaming and waving their arms like their hair is on fire. The guy looks at them with a look of total and complete terror, turns, and flees the compartment. What the officer didn't realize was that the displays were duplicated on the other side of the panel and that he hadn't affected a single thing on the boat.
They never had a problem with that sort of drill for the rest of the cruise.