One late night when I was working as an A&P, me and a buddy where trying to gain access to an ELT on a jet. The screws were frozen on the cover so were gave it a little elbow grease. Somehow we set it off, turned the radio to 121.5 and to our horror heard the blare loud and effing clear. We spent the next 15 minutes jumping in various airplanes trying to reach approach control on the radios, since the tower was closed. Then the owner called, grumpy and groggy wondering why NORAD was waking him up about his airplane that must have crashed somewhere when it should be down for maintenance. We laughed about it later, but at the time we were young and dumb and thought our careers were going up in smoke.