The electric company was having problems with "excessive bleed" of power in the area. Over a certain length of power line, they know there will be a certain amount of power "drop" from what was pumped in. Well, they thunk there was a grounding or something.
They sent out teams several times to no avail. One last time they sent out a team to check - and it had the same guy that had run the lines in the first place. He just happened to look up and see a connection he didn't recognize... which was the illegal electrical connection to this very house.
They called the cops and hilarity ensued.
Sheer, dumb luck.