2. Bed sheet ghost
Before I talk about the bed sheet ghost. Most ghosts that we know of are those that have no physical body, no feet, floating about, dull and are mostly or fully transparent. These are the common appearance that we call a ghost.
Also, call me crazy but I’ve seen white misty ghosts when I was a kid even before I knew the concept of ghosts. So it wasn’t scary until I was told what a ghost was.
So where does a bed sheet fit in all of this? There’s a possibility that they came from the burial shroud which are usually a white cloth that bound and covered the corpse from head to toe. But during the renaissance, which was the time when plays were a very big form of entertainment, they had to find something to depict a ghost on the stage.
They started off with heavy armor but as time goes on, it became funny as the sound of armor always made it impossible to jump scare the audience thus actors began appearing draped in white cloth to portray ghosts.
It became a thing because it is the easiest form of costume someone can make. But it is scary, if you imagine something just materializing under the blanket, not moving, not saying a word, just a bump in the blanket. Exactly like that one Dr. Who episode called Listen because the unknown is always scary.