Many cultures have their own version of the Boogeyman. A monster that lurks in the darkness, waiting to take children away to their shadowy domain. The weird thing is that sometimes, kids see it before they even hear the stories about them. They feel the presence of something in their room, sometimes just outside their door or at the far end of a dark hallway.
It is quite probable that this "monster" actually evolved as a survival technique, dating back to times when humans were tribal dwelling folk. If a small child wandered away from the camp, especially at night, chances are it would never been seen again. This fear may have developed simply to make sure we stayed in the safety of our own villages.
But suppose, for a moment, that there is some validity to the idea of this supernatural being.
Isn't it entirely possible it is not at all evil or malicious. Many people believe in guardian angels. How do we know these aren't simply our guardians keeping an eye on us. The idea that an angel would use fear to keep us safe may sound strange, but the most efficient rulers tend to employ Machiavellian philosophy. It is better to rule with fear, than love, but it is better to rule with love, than hate.
And while we're on the subject of the monster being real, have you ever heard of thoughtform? Thoughtform is the manifestation of mental energy. If enough people are pouring energy into the idea of a Boogeyman, after a while, it will show up.
So, when you lie awake at night, unable to sleep, what do you think about? Do you think about all the stressful things you have to do the next day? Perhaps it's anticipation for some event that is approaching. Or is it because of the sensation that you are being watched in the dark? The feeling you get from unseen eyes, as they silently observe you tossing and turning in bed. The thought of knowing that even though you are safe in your own room, there is a creature lying in wait, just beyond the foot of your bed.