"Scary Actual Vampire Sighting" is a YouTube originated screamer uploaded close to Halloween of 2008. It was made by user wickydkewl.
On-screen text starts things off, where it mentions that back in 1892, Mercy Brown, a 19 year old girl, was buried at the Rhode Island cemetery. It goes on to describe that she was conceived to be a vampire, and the user wants to see if this is true by finding her grave. He drives his truck to the graveyard, and eventually encounters a headstone with Mercy's name on it. Not too long when it gets screen time however, footage of the user himself coated with red paint pops up and lets out a falsetto scream. "Happy Halloween" appears by the end.
NOTE: The following video contains a screamer.