Psychology says people who keep their lights on while sleeping aren't afraid of the dark, they may be fighting a different battle of control and comfort inside their minds

Sleeping with the lights on is rarely an arbitrary habit. Psychology suggests that everyday behaviors often serve as clues to deeper emotional needs rather than simple labels. The real story is not the light itself, but what that light may symbolize for the person relying on it.

Raccontata daeconomictimes.indiatimes.com