When I was about 2 or 3 I saw what I thought was a goblin or something coming out from behind my chest of drawers in my bedroom as I was being carried past it. It seemed real enough at the time, and it really scared me.
When I was about 10, I became interested in the paranormal. I did seem to have some psychic ability, but because of my JWishness, I downplayed it and tried to ignore it.
Yet, I don't recall actually being terrified of them. I had the usual JW superstitions that the demons were watching everything I said and did, and that I had to be careful of not "inviting them into your home" via TV programmes or books on the occult, or even music with backmasking or by certain groups that looked like they worshipped the Devil.
Now, I do believe that Satan and the demons exist, but I don't believe that they are responsible for every kind of supernatural activity.