Dh and I were visiting my parents. We have, on rare occasion, used their address for ourselves when we were in the middle of a move. It just so happened that someone called and asked for us when we happened to be visiting.
Turned out we were due $18,000 (IIRC) for a class action. I don't want to say too much as it reveals some personal things, but the actual issue affected us in no way. Essentially, we signed a contract that said the deposit was nonrefundable, and in this particular case, that was agains the law. They had to offer refunds for those who backed out. We didn't back out, and never considered backing out, so were unaffected, but we were still part of the class action. That was certainly a nice, unexpected chunk of change!
And had they not found us at my parents' that day, I wonder how long it would have taken them to track us down.