Are ghosts corporal? Obviously not -- the corpse is buried. But folklore frequently has ghosts that can do quite corporeal things. There's a Norse legend where the ghost is in the habit of wrestling with those it meets -- and it's a good wrestler.
And even if it had the power to move the corpse from the grave without opening it, there are the grateful dead. They can pass themselves off as completely human until he end of the story. And then only because they reveal the truth. But the entire point of a grateful dead story -- what exactly inspires the gratitude -- is that the corpse is buried.
And then you get the ones that reappear as talking animals. Or a tree and doves -- well, maybe Cinderella's mother was guiding those, not actually was those. . . .