Never wrapped with electrical tape, but I just do basic stuff and would also never open a box that was still powered.
I have an old house, still have a few runs of the old aluminum two wire stuff, wrapped in black fabric. Asbestos I assume, lol. I've been replacing them as I find them and in the process have run across some really jacked up stuff. Shared neutrals for no apparent reason, really shoddy connections in junction boxes, all the usual nonsense. It's amazing that we have so few electrical fires in this country, especially in the northeast with many 100+ year old houses with original wiring.