I made a coffin from scrap wood for the cemetery a couple of years ago. I have since turned it into a hiding place for my fog machine and fog chiller. I have always thought that it was a waste not to have some kind of corpse or something inside it; but the fog machine and fog chiller occupy all of the available space. This year, as a quickie, afterthought kind of thing I made a couple of forearms and hands. I stuck them inside the coffin so that they were lifting the lid just enough to stick a foam skull inside the coffin resting on top of the fog chiller.
This prop is quite cheesy; but I wanted the coffin to be more like a prop than just a housing for the fog machine and fog chiller.