Sounds that ye old Knob and Tube stuff. I used to own a house that was
full of it. It looked like 18 gauge black cloth or paper wrapped
wires. The wires were run through ceramic tubes where they went
through a stud or joist and were suspended off of the wood surfaces
with ceramic blocks that were nailed down.

Yeah my hunch too, I asked about grounding since I helped a friend.
Turned out she had K&T and it APPEARED grounded

The trouble was a former owner connected grounds and neutrals together.
We found this opening a wall after a fire.On the outside a nice box
with 3 prong outlet. Buried in wall K&T grounds and neutrals tied
together.

The homes wiring was a patchwork quilt of bad stuff it was all replaced.