One reason I pushed for replacing all the switches and outlets

[Bruno1949]

and even the wiring if possible in an old home is from personal experience with this house. Not to mention that the OP was basically rewiring the entire house anyway, why not do it completely?

1. Outlet in back bathroom was ‘distorted’. My guess, after a winter in this house, is that someone kept an electric heater running in there all winter to prevent freezing pipes. The outlet actually worked yet but when I went to replace it with the proper 20 Amp GFI unit the outlet literally fell apart! And the wires inside the conduit were melted. Not shorted to each other, or to the conduit, YET, but melted. Obviously everything was gutted and replaced at that point.

2. Wiring to the den/men’s parlor/bedroom on the first floor was intermittent. I started opening junction boxes in the basement until I found the reason. Someone had, at one time, wrapped a wire around a cut in the insulation of one circuit and then covered the ‘junction’ with electrical tape and stuffed it into the back of the box. That wire was 18 gauge stranded wire! And it was powering all the outlets in my den!

I had several very old porcelain bodied light switches that would light up the room when you switched them! The back side of the switch plates had soot and arc marks on them! Yes, the switches worked but they were open bodied and filled with 100 years of dust, dirt, and other junk. I have replaced all of them but I’m keeping them for a museum display. Maybe. At least they aren’t in my walls!

My house has been wired, miswired, and rewired many times over the last 115 years. The last update was probably in the 1960s or 1970s from the looks of it. By the time I’m done there will not be a single piece of old wiring in this house. Whether required by code or not I’m capable of replacing all of it just for my own peace of mind and I’m going to.

Yes, reaching ceiling fixtures and some others can be ‘interesting’ at times, but normally only minor wall or ceiling plaster repair will be necessary if done properly. Using ‘fish tape’ and rods can snake wires to a lot of hard to reach spots with only small holes.