Egyptian
Egyptian texts & symbolisms contain lots of oddities. Many may be secret puns & jokes by the aristocrats, especially since homonyms are a central feature of Egyptian hieroglyphic script. You’ll also be surprised how many words are shared between Egyptian & Semitic dialects.
There seems to be no direct continuity to modern spooks, but I still suspect the Egyptian god-kings of proto-spookery.
Please read the introduction to Egyptian.