2 films match Possessor

Possessor follows an agent who works for a secretive organization that uses brain-implant technology to inhabit other people's bodies - ultimately driving them to commit assassinations for high-paying clients. (imdb)

This movie starts with the teenager Peter (Jean-Claude Verne) who takes a picture of a mysterious naked woman (Mimma Monticelli) near a pastoral waterfall. When the picture is developed, the woman's image is gone, and Peter is possessed by her ghost through a cursed amulet he finds at the scene. (imdb)