We very nearly left a recently-deceased bird for our purcjhasers...
For complicated reasons, we moved our stuff out before the sale completed. While it was empty, I went back to clean. only to find that a bird - quite a large one - had got in, probably down the chimney, flown around the place panicking and pooing everywhere, then died in the fireplace with one beady eye fixed on the sitting room door...
I cleaned it all up, and the new owners were none the wiser.
In our first house, the owner removed the cooker by the simple expedient of cutting the power cable almost flush with the wall, from which about 1.5 cm of it emerged, having been badly plastered in behind the kitchen tiles. Unfortunately, he came back to 'collect his mushroom log' while we were painstakingly removing said wire individual strand by strand with pliers, with everything switched off at the mains. In January. We weren't desperately polite.
In our current house, neither the electricians nor plumbers would consent to us moving in until they had made everything safe. Even then, we had to keep away from the windows on windy nights, because the widows flexed so badly (individual leaded panes) they could easily have exploded inwards, scattering shards everywhere...