I grew up in the '70s and '80s, and watched plenty of filmstrips in school. Although we normally watched them in class, sometimes we would be able to watch a private viewing on a small screen in our media center (what we called our library).
I recall watching one around 1979 or 1980 about vampires. It think it involved a young boy who lived in a town plagued by a vampire, possibly around the turn of the century. At some point in the filmstrip, a panel showed him sitting straight up in bed with a look of horror on his face. I think it was implied that he had realized that he was the vampire. Music then started to play with a stereotypical Bela Lugosi-sounding vampire voiceover, mentioning how vampires had stricken fear into people for over 500 generations.
The part with the boy realizing that he was the vampire scared me the most. That part caused me to lose sleep. I guess no child likes to consider the possibility of the monster within.
Did anyone else see this filmstrip? Can anyone tell me what the title was?