When I was a kid working with me old man the sparky left his wires sticking out his boxes me dad said leave them in the box and I will clean them leave them out and I will fill them in. So he filled them in and the sparky crossed charged him. on the next houses me dad took the nail out of his capping on a couple of chases and put it back in straight through the wire. Chases had to be chopped out to find the fault and sparky got charged for it. Me old man said u won't fookin cross charge us again.