repairing electrical outlets in old Plaster lath walls
i rewired my old house completely which has wood lath and plaster.
when needed, i found on average a piece of 3/8" drywall planed in perfectly with the finished plaster when installed over the lath.
so if the area around your receptacles is all chewed up, i would say to either use "durabond" compound and fill in the horror, or if it's really bad and bigger than say 1/2", you can peel off some plaster, and PL/liquid nails a piece of 3/8" rock right on over the lath. then just tape/compound per usual. maybe one or two drywall screws to hold it until the glue cures, or tape, even. worked like a charm in my place.
i used a jigsaw to cut out the holes for new boxes, and in a few cases broke the upper or lower piece of lath. if this is the case, just open up to next sound piece of lath. you can use the "old work" plastic receptacles and clamp them right onto the lath/drywall.
or replace the lath if really needed.
any of the above methods will get you there, depending on how bad things are.