She worked for a small cabling company. They were setting up the server room in a new office building. They kept getting readings off the charts, and couldn't figure out why. Someone saw the main power for the building came in on the other side of the wall from the server room. They checked from the metal beam at the roof to what was supposed to be ground and found a 4v difference.

Boss told them all to just drop their gear, walk out without touching anything, and call the electric company. It took two more hours of yelling over the phone before the electic company -- who did the install themselves -- would believe a small contractor and send someone to test it.