I was at an older home lately, it was around 40 years old, and I was there because the owner called me about some wires that were sticking out of the wall after they were doing some drywall repair work. They were afraid that maybe some or all of the extra wires were "live" and that they may get shocked.
Well, as it turns out, one of the wires was live. And, the end of the wire was bare. Somehow, it had become energized when the current owner hooked it up to another wire by mistake.
Folks, do me a favor, call me when you run into a situation where you see extra wires. I can help you trace, and tag wires so you won't be 'shocked" to find unidentified wires in the future.
For more reading on common electrical problems, click here: Common Electrical Problems