When my kids were little we'd bolt down to the basement after we put them to bed. I had a 4' ripper of plywood I'd wedge under the doorknob, to prevent unexpected interruptions.
One time in the middle of it all, we heard something, looked and there was a little hand clawing from under the door. Kind of ruined the mood.
All I can picture is the alien hand reaching under the door in the movie Signs.