Demonic possession

A common trope in fantasy and horror, involving (a) a supernatural being (a "demon") whose invisible essence can "inhabit" or "possess" a human being.

Examples in literature and film are numerous, beginning with the famed film "The Exorcist".

For more recent takes on the genre see:

• Come Closer by Sara Gran, a psychological horror novel in which possession eels like going mad -- this plays on the folk superstitions associating madness and possession
• the urban fantasy genre series by Jenna Black, beginning with The Devil Inside

Relatedly see:

• The Dyke and the Dybbuk by Ellen Galford, possession by a Jewish spirit
• Down a Dark Hall by Lois Duncan, induced possession by the ghosts of artistic and musical masters