Solway Firth Astronaut
Jim Templeton was in a marsh taking photos of his young daughter and after getting them developed there appeared to have been a Spaceman in full astronaut gear standing behind her. Except there wasn’t anyone else around while they were there. Even Kodak verified that it was not tampered with.
WWI Airman ghost
This group picture of some soldiers was taken in 1919 so no photoshop has been used here. The photographer didn’t see that shadowed face when the picture was taken. First later some of the soldiers saw the picture and recognized the face as a fellow soldier named Freddy Jackson, who died in an accident caused by an airplane propeller two days earlier.