The Light is a "Void-Walker" (Void Walkers are entities in the In-Between) they will lure unsuspecting Tweeners by hiding in the darkness and creating a light with their eye to make them feel safe in, since light is something most monsters are sensitive to. Once a Tweener feels completely safe, they will then attack and kill them.
its uncommon to survive an encounter once they actually try attacking, however you can avoid an encounter by just avoiding all lights with no clear source
The Light is actually an Evolved Version of the Eye-Lights! they at one point evolved to be able to defend themselves against other monsters, since they were originally a target of monsters.
they grew a body and became more hostile, using their eye light to lure humans.
why did they wanna lure humans?
upon attacking humans, they scream, or atleast make some loud sounds, this draws monsters to the area, for The-Light to kill as revenge. (they also get a kick out of killing humans)
Usually found on levels -1, -2 and -3