Background: 100+ year old house with lots of really janky, messed up stuff. Some novice before me has been monkeying around, so don't assume that the current wiring is sane, safe, legal, modern etc.
I am experiencing a phenomenon where outlets and lights are failing. There does not seem to be any rhyme or reason- the outlets downstairs, the lights upstairs and several rooms in the basement all failed together and another went out last night, all for no apparent reason. We had an electrician look at it but he could not find fault in any accessible light switch, socket, outlet and exposed box and he pretty much just gave up. Of course, we checked the breakers. Unfortunately, the breakers are not mapped, so there's a mystery there as well.
The best answer that we can come up with is that either from old age or shoddy craftsmanship (or both) some wiring has broken somewhere within the walls or attic of the house. Short of tearing into the walls to get the wiring, is there any way to locate this break?