Spontaneous appliance activations and knocking in an old house

First time writing here, usually always in read-only mode, but the situation has become very interesting.

Background is as follows. I have a close friend living in a small settlement 50 km from the city in a big old private house that is about a hundred years old. It all started with TVs with built-in smart function starting to spontaneously turn on clips, music, and noticeably lag. Naturally, all these little things were automatically attributed to imperfect technology and we happily ignored them, a couple of times we wiped accounts, linked new ones, and it helped for a while.
Then the interesting stuff began.
Simultaneously with the glitchy TVs, a strange knocking appeared in the house (as if someone is pounding on a beam with a big mallet), it appeared mostly at night. Several times a full inspection of the house territory was carried out, even with a trip to the attic and roof, nothing was noticed, dogs and cats behaved as usual. Once I myself witnessed this knocking, but didn't pay attention to it, so as not to fill myself with unnecessary guesses and fears.
After some time the knocking stopped and the TVs started working stably. For about a month or so everything went on as usual.
And then problems with smartphones began on the territory of the house.
Spontaneous reboots, !factory reset!, sometimes Androids wouldn't start, some messengers and apps were deleted, - I heard all this from the words of my friend and his wife, until the next time I came to visit and saw my smartphone start endlessly rebooting before my eyes, I never had such problems with it. These problems plague them to this day.
Next comes the most hardcore part. Why did I decide to post this in paranormal? Initially we had some thoughts about what was happening, and even random interference from the military and their equipment, communications or who knows what they have there, fit into it, since between the settlement and the city there are military units with mobile nuclear weapons. By the way, the city is far from the western part of Russia and western borders.

But when the coffee maker (can't start without a button), microwave with a mechanical rotary control system, washing machine started turning on, my skepticism and purely scientific explanation/coincidence of circumstances began to fade into the background. I've only seen such things in typical American horror movies.

So summarizing this whole situation, there are several questions.

1. What is this?
2. If there are specialists in the fields of communications, communications, engineers, instrumentation and automation etc etc (I don't know), maybe there is an explanation for this. I didn't google anything except banal voltage fluctuations, but working devices don't turn off, and phones aren't connected to the mains. There are scheduled power outages, but no more. There are no voltage drops.
3. Maybe it really is the military? But the neighbors don't have such problems.
4. Maybe buy some kind of electromagnetic field/microwave radiation meter?

As for the technical stuff, fiber optics are installed in the house, a couple of routers, a couple of TVs, everything works off the internet, nothing cosmic.

In total, this whole story has been going on for about six months, so I will keep you posted on new events and changes.