Hi, new here and don't know a bunch about electricity but will try to be concise.

Background:1890's farmhouse. Looks like homeowner did wiring. We have lived here since 2000 with no major wiring problems but now this: One circuit breaker tripped a few times, we went and reset it, worked for a few days then tripped again. Now, about 1 week ago it would trip; we would reset it and it would trip as soon as it was reset. So, not knowing if it would cause a fire we left it tripped.

Strange circuit: Living room and den and front foyer and upstairs master BR.
We occasionally have the light switch in the downstairs foyer not work but we went upstairs and that switch would work the lights ( neighbor said that was just due to the lights not being wired properly???)

It appears as if most rooms have 2 circuits ( so you would always have some power?)

House is all plaster and lath so for the upstairs they ran all wiring up to the attic through the chimney chase? and then sent the wiriing to the individual rooms through the attic floor.

Where do we start: add up all the amps drawn by things plugged in to see if the breaker is too small?

No mice now but have had them in the past; could the wiring have been chewed?

Thanks for any light you can shed on this. ( pun intended!