An ordinary woman is getting ready for bed in her small apartment. She switches off the hall light and, in the darkness at the other end of the hall, she sees a shadow, A silhouette.
Something almost human. But not quite. She turns the lights back on, silhouette's gone "Turns lights off again, silhouette reappears."
A nifty visual that gets really creepy, really quickly. It plays on those moments of not quite trusting one's perceptions, of glimpsing something in the dark or from the corner of the eye and not being certain if it's real.