THE PLANT MANAGER WAS ASSISTING ELECTRICAL CONTRACTOR LOCATE A BROKEN WIRE TO THE BIN VIBRATORS. HE WAS ASKED TO ENTER THE POWER HOUSE AND MAKE A JUMPER WIRE TO JUMP ACROSS TWO POLES ON THE VI BRATOR SWITCH BOX. WHILE STRIPPING THE ENDS, ONE INADVERTENTLY CONTACTED TWO LEAD POSTS OF ANOTHER SWITCH BOX NEARBY, CAUSING A DEAD SHORT AND BURNING HIS HAND.