Here are some creepy examples of unexpected, ghostly patrons photobombing the living’s photo ops.  Plenty of examples provided here to get your hackles up.  Another frightening element to this video is the narrator’s robotic, sing song tone.  The entertainment value of this post just went up!
“In Search Of” was a documentary series hosted by actor Leonard Nimoy.  The show ran in the 1970’s and it’s subject matter covered the mysterious, the supernatural, the uncanny and the just plain weird.  Here is a sample episode that pursued the topic of Bigfoot.  I remember watching this program religiously on Sunday evenings and enjoying it immensely.  A precursor to the vast amount of supernatural/docudrama series which populate the cable TV landscape today.  Worth seeking out.