A ghost is the residue of a once living person that has 'unfinished business' and cannot leave this earthly sphere until that 'business' has been resolved.
A ghoul is a real living creature capable of reproduction amongst its own kind. It is a grotesque troll-like creature that feed on carrion, will enter the grave and feast upon the interred body.
ghoul
ghoul school
spook
Maybe ghost
ghoul
possibly cool ghoul
Apparition, phantasm, ghoul, spirit.
Gotta ghoul gotta ghost up in the walls.
Ghost, ghoul... etc.
go find a ghoul friendf
Specter or spectre is simply another word for ghost.
the ghost of Christmas past :)