Today whilst putting up shelves in my kitchen, I drilled through a pipe.... Luckily I didn't drill the entire way through. It was really soft metal and I just assumed it was maybe a bit of wood, or some brick behind the plaster. I should've looked. Ooops! Spoke to my dad and he thought maybe it was a old electicity cable by the way I described it, but said I should get it check out or buy one of those screwdrivers that checks whether something is live or not. There were no sparks, but then I didn't cut through the copper cables, though I think I nipped ones of them as there is a small scratch