This is an outlet at my in-laws’ house which was built in the 1960s. I’m not sure if this is just some paint that was put on an outlet and has worn off over time or if this is some residual evidence of sparking/minor electrical fire. The walls are wood panels painted white, so it seems to me someone might’ve just thought they could paint the outlets as well (there are some parts of this basement that don’t have the wood painted and the outlets/switches are dark brown, which might be what I’m seeing). The outlet seems to work but I don’t feel totally comfortable plugging something more expensive like my laptop in, even though I suppose the charger would be more likely to die than the actual computer. The house has a fairly new electrical panel with breakers that seem nice, but it was also built initially as a duplex (with a later addition making it useable as a triplex) and each part has its own old sub-panel that still uses twist-in fuses. I’m still not sure if whoever put in the new panel said the rest of the wiring/outlets was fine or my father-in-law just decided upgrading the rest was too expensive.
Someone painted the whole outlet when they painted the wall, then someone else replaced the face plate.
You shouldn't be concerned about what it'll do to something plugged in, you should be worried about the paint heating up to the point of combustion. The bubbling up causing the flaking may be indictive of that.
Now, it's been decades, and nothing's burnt down, but don't fuck around with electrical.
At some point that sub-panel needs updating, when that's getting done, have them change the outlet. And just a general look around will be a good idea.
It's probably fine to wait, but there's no reason to either.
US plugs are fucking wild. Like last century types of wild.