William H. Mumler is widely recognized as the first commercial spirit photographer. With studios located at 258 Washington Street in Boston and 630 Broadway in Manhattan, the businessman offered patrons an opportunity to obtain portraits with "departed spirits recognized as that of some relative or friend".
When visitors first arrived they were seated in a Chippendale chair and told to remain still until Mumler's wife Hannah, a clairvoyant medium, had summoned the spirits. Although it often took several attempts before a ghost image was developed, customers always left "fully satisfied that the pictures were what they claimed to be--real photographs of real spirits".
The above engraving from the Macabre Museum archive is a rare look inside Mumler's studio.
Fink II, Richard. The Commercialization of the Afterlife. (2010)
Kaplan, Louis. The Strange Case of William Mumler, Spirit Photographer. (2008)