"Ron" wrote in message

I can't find the circuit breakers for any of the upstair bedrooms in
this old, 1908 built house. Would it be reasonably safe to replace a
light switch wearing rubber gloves and rubber-soled shoes if it comes
down to having nno other options?

Only if competing for your own personal darwin award.

There is always a way. If worst comes to worst, shut off the main breaker
for long enough to do the job.