Lights Out (2013)

When you are all alone in a small dark room without a single beam of light to pierce through the palpable blackness, what do you fear the most? Is it the temporary blindness that sends shivers down your spine or does a more crippling and maddening fear possess you, stemming from an uneasy deep feeling that someone, or rather something, is observing your every move? But no, it surely can't be the latter; after all, monsters don't exist.