When I was working on Myrtle Cottage I found (apart from the rat's nests) empty lunch wrappers and drink cans and all sorts of builder's debris in the walls.
When we pulled the wall off the kitchen and WC at the child care centre, the electrical wiring was almost non-existent in the kitchen wall - eaten by things with teeth - but in the cavity of the WC wall we found drink containers, cigarette packets, and many, many cigarette butts, all of which seemed to have smouldered to extinction in the wall.
The cistern had been moved at least twice in the history of the building, leaving pipe sized holes in the plasterboard. Obviously, various occupants of the building (the family? the child care workers?) had enjoyed a quiet fag in the loo then flicked the butts through the holes. I noticed that none of the butts had been (a) butted, or (b) dunked! How a fire hadn't started in there with all the dust and fluff and paper is amazing!
When we also removed the wall furnace, we found that the hardwood timber framing had charcoaled inside the wall - that's how hot the furnace had been over many years!!
Again, at Myrtle Cottage, after the floor gave way under me while I was smashing and levering up the floor tiles (borers - eeeeuuuw! what a stink!), the vanity waste pipes were non-existent as they had been eatern away by the rats. So the owner had obviously not been big on washing his hands for a few years as the water would have run straight from the waste and into the cupboard. Mind you, one of the owners had died in the shower so perhaps that had something to do with it!
The nicest thing I have found was a piece of masonite nailed to the frame in the garage, with a history of servicing the motor vehicles chalked on the board. It was a lovely and nostalgic momento indicative of Saturday afternoons spent pottering about with cars in the years when people actually did those things!
Cheers
Kristine