My wife and I live in a small 'old by west-coast North America standards' cottage at the edge of a large patch of PNW rainforest. The property is fenced on three sides, the fourth has a dropoff leading to a creek, then the forest.
Three, maybe four months ago, we were home one evening; she was in the master bedroom watching Netflix, I was in the living room working on my computer and our dog was asleep on the loveseat next to my desk.
I heard a bang from the kitchen and went to investigate.
I was surprised that the dog didn't awaken, frankly. He's a border collie mix and keeping track of his flock is his purpose in life.
On entering the kitchen I discovered that one of my large, heavy 14" skillets had fallen from the stovetop to the floor.
As a rule, I'm very careful where and how I position my cooking utensils and I know damned well I hadn't left this one close to the edge of the stove.
Dog still asleep, I went to get my wife... she'd had her headphones on and hadn't heard the impact.
Before showing her the skillet, I asked her to confirm that the dog was, in fact, asleep on the couch. She agreed that, yes, he was still a-snooze.
Led her into the kitchen and pointed out the skillet. Asked if she had any ideas because I was at a loss to explain it.
She suggested the perhaps a mouse had run across the handle and knocked it over.
I was doubtful. We do have fieldmice that occasionally enter our house (again, old cottage, lots of gaps, minimal weather stripping, etc.) but I strongly doubt that they're weighty enough to tip over a 5lb skillet.
I picked the skillet up off the floor, placed it back on the burner and tried pushing down on the handle. It required noticeable force to even budge. She tried as well and agreed that, yep, that takes some doing.
One side of the skillet now has a dent from where it impacted the floor.
We've never really come up with a suitable explanation. Thinking that it might possibly have been a seismic event, I looked up the website for seismic activity in our area and... nothing.
No large trucks had driven down our road. It was fully night-time so no blasting from the development down the road. The front door was closed, locked and the deadbolt was engaged. The only other non-window point of entry is a door on the opposite end of the cottage that was similarly closed, double locked and deadbolted.
The only other strange thing about this cottage is that both my wife and I and our adult daughter who lives here in town have never once gone into the attic. All three of us get this unreasonable feeling of 'nope, I should not go up there' when we think about it. I've briefly poked my head up there with a bright flashlight... nothing unusual or out of place but still a strong feeling that I should not proceed further. I very rarely get that feeling in other contexts, but when I do I tend to heed it.