It is important to become familiar with how glass can reflect one's image and appear as an apparition, a false ghost photo. Glen Goodman sent us this example of his own reflection captured in glass. Notice how he is transparent, see-through:
-
A person reflected in glass appears see-through like an apparition...
"I took this picture attempting to view inside an office against a glass door. The ghost image is myself, so this picture is a good benchmark of how some ghost images can be caused by reflections."