Lai Qui

Drug courier Lousy Chao and his wife Ngor are killed by his boss, after being framed for drug substitution. His ghost finds a man with the same birthday, Ming, to help take revenge. The unfortunate Ming has just proposed to Hung, but Lousy hijacks his body, and starts by killing his immediate boss Shing Yiang To in a sauna. This alarms Shing's boss Nan. Meanwhile, the possessed Ming take nightclub host Jenny home for "late supper". Hung is sure something is amiss, and consults her taoist uncle Shun. Nan is further shaken when his partner Chuen is killed, but still keeps an appointment with Thai drug dealer Buddha. Up until this point, both Ming and Nan consider ghosts to be "bullshit", but they are soon convinced otherwise...

Hong Kong drama from the 1970s

One of the better possession movies filled with hexes, spells and exorcisms. It also contains crucifixion (well, sorta), lesbian sex, and flying skulls. The overall tone is dark and gelid.