Monk Spirit Ghost Picture

"In May of 2005, I visited England. While touring Rufford County Park in Nottinghamshire, I took pictures in one of the lower chambers of the Abbey there. It was the Monks old dining area. I do not know thehistory of the building, but I got a surprise when I began looking at the pictures. There appears to be an apparition of a monk (or something) in the attached photo. It is standing next to the window on the right,just behind the Monks table. I know there was no one there when I took this photo. There were only two of us in the chamber and we were standing side by side. Just wanted to share it with you. It may not be anything, or just tricks of light on the uneven walls, but it is very strange. Maybe you can sort it out.."