'Lights Out' trailer unleashes unknown terror that lurks in the dark

The first trailer of upcoming horror film "Lights Out" proves that you were right to be afraid of the dark.

From "The Conjuring" producer James Wan, the movie revolves around a family threatened by an unknown entity that only appears once the lights go out.

The film stars Teresa Palmer, Gabriel Bateman, Billy Burke, Alexander DiPersia, and Maria Bello.

David F. Sandberg will be debuting his first feature film with "Lights Out."

It will open in the Philippines on July 21. —Jessica Bartolome/JST, GMA News