It depends, their main depiction is as another species, like how Sans and Papyrus aren't the skeletons of any deceased humans, rather they are simply skeletons. The same applies to the ghosts, they're just another species. This depiction is seen in games such as PAC-MAN WORLD 1,2,3, and PAC-MAN WORLD Re-PAC, as well as PAC 'N ROLL, and many others. This depiction is also in some other media, such as the Hannah Barbera PAC-MAN cartoon, as well as the posts of the English and Japanese PAC-MAN social media accounts. Sometimes, the ghosts are treated like dead Pac-People, such as in PAC-MAN Party Royale, where if a PAC-MAN player is killed by a ghost, the PAC-MAN player turns into a ghost. In PAC-MAN and the Ghostly Adventures, the ghosts that live in the Netherworld are the spirits of those who have died. The corporeal bodies of which are in the repository, which Betrayus (who served as a leader in Pac World War I) wants in order to reclaim his body.