Time does it very often something triggers it in
the begining but many children are afraid
of the dark, best to let them have a hall light on ,with the bedroom door open,I dont think it is something that you can help them get over, as they get older it dissipates , I was a child like this , Trauma triggered it and it contiunued through my childhood, but it went once I became a teen,I still like the bedroom door open but I am not afraid of the dark...