ghoul vs evil spirit

ghoul and evil spirit both are nouns.

Word	Noun	Adjective	Verb	Adverb
ghoul	Yes	No	No	No
evil spirit	Yes	No	No	No

As nouns, evil spirit is a hypernym of ghoul; that is, evil spirit is a word with a broader meaning than ghoul:

ghoul (noun)	evil spirit (noun)
an evil spirit or ghost	a spirit tending to cause harm
someone who takes bodies from graves and sells them for anatomical dissection