The whole idea of racial issues being tied up in this really got me thinking.

Another word for ghost is spook - and we've a whole minefield of racial connotation there,

While 'spook' has been used by Black people in reference to a white person, in particular white musicians I think, as a nod to skills with certain music styles considered 'Black' (someone please correct me if I have that wrong!). Playing so well he must be the (white) ghost of a Black man?

Then 'spook' has also usage as derogatory slang, originally used by white pilots in the 1940s (WWII), who began calling Black pilots the 'spookwaffe', again I think I have this right that it was originally meant in reference to the darkness of their skin making them less visible in the night sky? (So in a sense similar to using 'spook' to mean spy). Unfortunately the term was carried on into common racial slur.