In Search Of... Ghosts
But why? Because Mr. Spock, a trusted friend and comrade was now telling you about scary shit like demons, witchcraft, and worst of all Ghosts.[1]
Anecdotal Evidence
Every once in a while, people online will ask you what terrified you when you were a child. I gotta say that the Ghosts episode of In Search Of... scared me boneless. I watched the episode with my sister, who was 10 years older than me (I was six) and I didn't sleep for six weeks. I was certain that a nameless entity would enter my room and do something horrible.
If you don't remember, or are too young to know this, at the time the episode aired, heavy metal music was under fire for being demonic. Also, movies like The Exorcist[2] and The Amityville Horror[3] were really popular. Every kid back in those days thought that their attic or basement housed the portal to Hell.