"I took this picture with my cell phone on a ghost tour in Chicago at the Hull House Muesem. My cell has no flash and I've never had any weird pictures with it before. Also, no one else was present in that area when I took the picture."
Note: It might be just a reflection. Perhaps there was glass or plastic between the photographer and the scene? You can see the large face of what I think is the photographer. The light upper right also seems to be a reflection. So the image of what appears to be an elderly man in (perhaps) period clothing and white shirt could be a reflection. But Erin says there was no one else around to reflect.
Even if it is a reflection, it does not rule out the possibility of a ghost. Many reseearchers believe that ghost images are more readily captured in reflective surfaces.
Erin responds: "I was standing outside the door taking the picture through the glass. I do have some that I am reflected in and you can tell it's me because I was wearing blue. So I'm positive the image on the stairs is not me. I also know that it was not anyone from the tour as it was hot, and everyone was wearing shorts and t-shirts. Plus, by the time I took that picture they had moved on to explore the garden."
- from Erin Zinth