Fear of the dark

Doesn't everybody some times get the feeling they're being watched? Especially when you're all alone in the dark, there seems to be something there. Why? Is there anybody out there? Or is that just the someone in there trying to make contact?

When you're alone, all you have is yourself, obviously. Is that what we fear, being alone so long that we have to face our own shit and see ourselves in the mirror? Or is there something else lurking, the christian Devil or the Daemons of the past, waiting for an opportunity to seize you into the underworld? 

Personally I think every demon is just another aspect of your personality, another fragment of the person you are. But even knowing this, I fear sometimes. When I am all alone in the dark, I get goosebumps and turn on the light again. Is darkness the only mirror where we can see our true selves?