I'm glad you noticed, as that was the lil fun bit I was hoping someone would catch on to.

The outlet that doesn't seem to consume from my mains, does get shut down when I pull my main breaker.

And as a response to what TheRealLinga said, oh hell no. If I don't know what breaker is behind that socket, I'm not going to power anything from it. I like living here, I'm not going to risk burning down the building XD

Only way I see the ghost power socket can work is if its on a relay that gets switched from my power while switching an outside source.

There however is no relay to be found in the panel or anywhere else accessible.

My apartment takes up the entire floor, but other floors have 2-6 units. When I go by the layout of the 4 unit floors, the location of this outlet is about where those floors maintenance room is.

So what I'm suspecting is that at one point, my floor also had 4 units, then got gutted completely and my apartment was built in it and then for some reason they wired that outlet rather than just cut and terminate the wires.

Still leaves the mystery why the other outlet, that does clearly draw power from my mains, also seems to be wired without a breaker.

I'm not in the US.

But from my experimentation with the breakers and power draw and graphing my power consumption and a load of other stuff on Grafana, should be clear I'm informed and smart enough to not use sockets that I don't know the limits for. So don't worry, I'm not using them at all.

But it's still an interesting mystery I enjoy trying to get to the bottom of.

The buildings megastructure is quite old, it was one of the few buildings that survived WW2 without much damage in this area.

It was originally a brewery, then a garment factory, then a nunnery and in the late 80's was gutted and converted to an apartment building.

The wiring plan I have for my apartment is from 2008, which I suspect is when the previous owner gutted the entire floor and installed the single apartment where there used to be 4.