The evil little creatures in my bedroom.
Okay, well, I don't do this anymore, but not too long ago, I used to comfort myself at night by telling myself that only 0.00001%% of the things in my room are evil, and they are located in the furthest back corner and can't reach me.
And also, if I take a bathroom break in the middle of the night, walking in the dark, I tend to walk faster or run toward the light to escape the shadows because I believed things will come out from the shadows to get me.
I'm actually not afraid of the dark; I love the dark, but sometimes my imagination runs wild, I guess?