Sure, it's just paint. If there are other issues like the plugs not being retained, then just replace it. They're dirt cheap.
Electricians
Based on where it's worn off, I'm 90% certain that's just paint. That being said, it's a cheap enough fix that you should really just do it.
From that photo alone, that looks like someone didn't want to deal with changing the outlets when they painted the walls and that's just paint warn off of a dark brown receptacle from many years of plugs being inserted.
As one who has done many dumb things in my life, evidence of small electrical fires would be whispy smokey gray possibly with some meltiness.
Side note, autocorrect tried to make "dumb" be "fun" and I couldn't feel more seen right now.
If this is the only receptacle in the house that is causing some unease, then it's simple and cheap enough to replace the receptacle. Around me, the cheapest UL-listed duplex receptacle at the home improvement store is less than $3. For the "commercial-grade" receptacle with my preferred backwire terminations, about $6. For TR-rating, $8 out the door.
Someone that's handy (and careful) with electricity should be able to swap it out in 20 minutes, and then you won't have to worry. Of course, as with all home improvement, don't do it yourself unless you're reasonably confident. And opening the outlet box might reveal new issues. But there's only one way to find out for sure.
I think there’s another one in the room that looks basically the same, but again, probably just paint. Normally I’m perfectly comfortable swapping out an outlet or light switch, but those have all been newer houses with breakers and copper wiring. I think this house was built in 1966, maybe 1962, and I have no idea what the wiring standards in Quebec required at that time. I might try looking at it more on this visit, though.
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