I still usually keep a light on when I go to bed. It's not because I'm afraid of the dark but that I'm so used to it after years of doing so that I can't fall asleep in total darkness. I can have just a small candle going and that's fine, but complete blackness? How the hell are you supposed to find the light switch if you need to get up before morning? Is a nightlight your solution? Yeah, now it is, but back in the day, nightlights were only for "sissies". Shows how much you know, you ignorant...sorry, I don't want to drift off topic.
When I was a kid I always had to have a light on and the door open, even if it was just a crack. Parents always seem too eager to shut their children up in a dark room and leave them to fight the monsters themselves. It's not right! How do you know there are not monsters and evil things lurking in the shadows? You don't!
Children are sometimes much more aware than adults, and on this one the kids have got the grown-ups wearing dunce caps. So leave the light on (the demons hate it).