Since the beginning of photography, people have manipulated the medium for artistic effect. Early spirit photography (middle image) was often the result of long exposures and darkroom trickery. Cameras, like typewriters, are thought to act as mediums between our world and the next. Even current digital technology can produce some otherworldy images (whether authentic or via manipulation, that's for you to decide!)
The final image is by Denise Grünstein, as posted earlier.