As a child, I had a closet that had the slatted doors. I was absolutely convinced that Freddy Kruger was hiding in there. It was worse with the light on - then I would be able to see his shadow as he dragged his creepy knife-y fingers over the slats and i am officially creeping myself out, so nevermind, this is clearly not a silly fear!
...I was, however, afraid of turtlenecks. I'm still afraid of them, but I know now that it's silly. They won't come alive and choke me, i'll just get stuck trying to put it on and asphyxiate and die that way. That's much more reassuring.