In 1994 or so I decided to move our computer up to my bedroom. I knew that there were no grounded outlets upstairs, but assumed I just had to replace a couple of outlets, grounding them to the boxes. NOPE. There were no ground wires anywhere, and the wiring was nightmarish, with exposed copper in one spot. So bad that that triggered a major rewiring project that took me most of a year, but still only replaced about 70% of the wiring. I hate old houses...