outlet wall plates
Also make sure your screws in your outlet wall plates are vertical. I've found it's a key tell between mediocre electricians & handymen, and the real pros, and it gives me confidence (perhaps unfounded) that the electrical systems are in good shape.
That's funny - I always align the screws in the wall plates when I (re)install them, but imagined that to be an idiosyncratic bit of fastidiousness. I've never noticed anyone else having done it.
Eh. I've been working (at $job) with an electrician I will be thrilled to see the back of, and whom (the feeling is general) we will never hire again, and... The screws are aligned, but eldritch horrors lurk beneath. That might once have been a useful heuristic, but too many have caught on to it.