My wife Anita and I were cleaning up our house that we were moving from to a new state.  We had already sold it, and the new owners had already taken possession, but for some reason we were inside finding stuff we had left behind.  We were in the attic, which was a big place, not crawl space, and there were big clumps of dust clinging to all the walls which could easily be swept off.  There was an exit to the roof, where I found a lot of old clothes that had been intended for Goodwill and somehow had been left on the roof instead; they had gotten wet from rain.  There were also some nice building materials inside.  We asked someone --a realtor, presumably-if we could leave those, and she said we could.  We were going to clean everything up, but it was going to take some time, and we didn't know when the owners would come home and what we would tell them.  Anita apparently went ahead and engaged a cleaning service, because two men came, and one of them had a vacuum cleaner.  It was such a huge task facing us, that for a moment I was actually willing to pay them to clean it.  But then I realized we were under no obligation to clean it, because the sale had already taken place, and we had no responsibility whatsoever for any conditions which may have been present when they accepted the sale or which developed later, so I let the cleaning crew go.