One bitterly cold winter weekend when I was in high school, the rest of my family went away while I remained alone at our house in a woodsy part of suburban New York. There was no moon to light the woods surrounding the house, but I nonetheless loved having the place to myself so I could stay up all night watching movies, eating junk, and smoking cigarettes into the fan over the stove.
At about 3:30 AM, I was cozily ensconced in the den and had just decided to go upstairs and go to bed, when suddenly I was stunned and chilled by the sound of our garage door going up. Without giving myself time to think it through, I went charging to the garage and pressed the button to send the door back down. Thankfully, I had the car in the garage, so I didn't have to worry about someone having broken into it to access the garage door opener. BUT, this meant I did have to worry about someone crouching unseen behind the car. I was standing in the doorway leading from the kitchen to the garage, which was down a couple of steps. I couldn't man up to the point of going to look myself, so instead I pushed my Jack Russell Terrier into the garage (I must have been REALLY terrified to do this because I loved that dog!).
She calmly nosed around for a minute or two, with evidently no idea that something could be wrong. I knew that if anyone had been in there, she would have picked up on it immediately, so I felt assured that no one had entered the house. I brought her back inside and probably kept her with me after I had returned to the den and put in a cheerful comedy to watch until daybreak, at which point I locked us both into my bedroom and went to sleep.
Later, I told my mother about the occurence over the phone. My parents had friends from home staying with them at our weekend place, and the wife told my mother that the garage door at their house had repeatedly gone up on its own the previous week. They had decided that it was the extreme cold that was causing it to do this. I had never heard of cold weather having this effect on a garage door and haven't heard of it since, but it was the only explanation at hand. These friends' house was almost right around the corner from ours, but I I suppose I decided that, in the unlikely event that someone was trolling the neighborhood at all hours with some sort of master garage door opener, they were contenting themselves with leaving once the doors were open.