From the summer of 1961 to the summer of '63 I worked the midnight-to 5 a.m. shift in a radio station and went to college during the day. The broadcast studio was in an old house on the north side of town. The house probably dated to the 'Twenties, but by the 'Sixties the area was classified as "light industrial." Lots of small shops and manufacturing facilities, busy during the day but deserted at night.
When the night man left at midnight I locked both doors and checked all the windows to make sure they were locked, too. Then I locked the door to the control room. The final line of defense was a 1911 in a holster screwed to the underside of the console where I sat. I had been shooting since the age of six or so and had fired a 1911, so I felt pretty safe. Except for...
Three times during the two years I worked that job I got a sudden and strong feeling that, to co-opt the title of the Ray Bradbury novel, something wicked this way comes. Other posters to this thread have mentioned a profound silence. That's what I experienced. There weren't things going "bump" in the night. Conversely, things were so quiet I could hear the soft hiss of the needle on the record and the thudding of my heart, which had suddenly jumped from my normal 50 beats per minute to 100 or more. At the same time, I began to tingle all over. Years later a doctor friend told me that was my system being flooded with adrenaline.
All three times I took the .45 out of its holster and made the rounds of the control room. The window in the outside wall had been sealed up when the soundproofing was put in, but the wall on the hall and the wall between the control room and the room next door were glass--not bulletproof but three-quarter inch laminated glass for soundproofing. It would have been hard to break thru.
Nothing ever happened. No visits from lions, tigers, bears, ghosts, or zombies. After half an hour or so the feeling went away as quickly as it had come. I asked the night man, who worked 7 p.m. to midnight, if he had ever experienced anything like that. He said no, but the look he gave me said otherwise.
One final comment here. When you're a shooter, comfortable with guns and confident of your ability to shoot them, it's amazing how much better you feel at times like that when you have a gun in your hand.