I was shutting the house down for the night, making sure the doors were locked, turning off the lights, and the cordless phone in my hand (I was taking it back to the charger) rings. Well, it was late for the home phone to be ringing, so I instinctively looked at the caller id. It said "10". Nothing else.
There were three levels of thought here. My first mature thought was, "Weird. I'll see if they leave a message." My next semi-mature thought was, "This makes me think of the movie where the guy calls the babysitter and says, 'Have you checked the children?'" And, finally, my completely twelve-year-old girl thought was, "OMG! In that movie the call was coming from inside the house!"
And, thus, I scared the ever-living crap out of myself with a 1980s B-movie.
P.S. They did leave a message. It was a butt-dial. I don't know who. But, if I ever figure it out, I'm gonna smack 'em for having a caller id of "10".