So I'm up early in Santa Barbara, where I'm alone for the week. Usually my bladder wakes me up around 4am. After doing my business in near-dark (so bright light won't start my day), I go back to bed. Half the time I fall back to sleep.
This time was different, because a sound in the house woke me up. I doubted it was human, or even animal. Most likely mechanical. But... what?
So I sat still for 20 minutes, listening through the nothing of house sounds... a ticking clock on the kitchen counter... the hot water recirculating pump in the basement... relying on hearing that is not what it used to be but also not what it will be when I finally need hearing aids. (I've been tested: I don't yet.) And I heard: nothing. So I went back to bed, where the loudest sound was my heart. And didn't sleep.
Then came the sound of a weight shifting somewhere. Something slid, maybe, and a floorboard creaked. So I walked around, hearing nothing new, and finally stood still in the kitchen for a minute or two. And there it was again. The follicles in my scalp tried to stand their lost or doomed hairs on end, and my body froze in place
I listened for another few minutes, stone still, hyper-alert. Nothing.
Then I said fuck it to the whole worry, turned the lights on, started the espresso machine (which makes heating noises), and went up to my office, yawning my way into the day.
Postscript: this happened two days in a row, and on the second I heard news that there had been small earthquakes in Ventura. When I checked the timing, sure enough, three of the earthquakes matched exactly when I heard the noises. Mystery solved? I dunno. Maybe.