Vimeo's Staff Picks are often very good, the pinnacle of "user-generated content" as the industry jargon calls it.
The short horror film (it's less than three minutes long) Lights Out does a lot with a little and is highly inappropriate for children -- not because it's violent, or filled with adult images they're not ready for, but rather because it shows them exactly why we're all afraid of the dark. It won awards for a reason.
Lights Out - Who's There Film Challenge (2013) from David F. Sandberg on Vimeo.
Sleep tight.