the worst shock you can get, is the one you don't figure you can get. like a old timer with me, i was working on a 277 volt lighting circuit in a 1x4 hole for a light fixture, and the old timer, mike, said to me, don't worry i shut it off. well i reached in the ceiling to pull the wires out of the box and i got hit with 277 volts, mike shut off the wrong circuit. at the time we were still allowed to smoke in buildings, and i spit my cigarette half way across the room and don't remember coming off the 6 ft. ladder. all mike said was, SORRY