In 1872, Mary Todd Lincoln went to a ‘spiritualist’ photographer who could show in a picture what she had always believed: that her late husband, President Lincoln never left her side. She liked the picture, and refused to believe that it was a fake. Three years later she was committed to an insane asylum.
This 1922 photo is said to show a ghost wedding. The woman is supposedly a nǚ guǐ (女鬼), or ghost woman: a woman who died unmarried has no family and can't become an ancestor, so she returns and haunts. There's a simple solution to the nǚ guǐ hauntings, though: find a man and pay him to marry her. These "profound weddings" (冥婚) are an important function of the Dàoshi, and a kinder form of exorcism.