On Friday, August 11, 2017 at 1:04:53 PM UTC-4, KenK wrote:

As a last resort, you can turn off the main breaker for the residence
then safely remove the switch for testing.

Then I can't see what I'm doing. No one to hold a flashlight.

My headlamp has saved me in similar situations many times. That purchase was one of the smarter things I've done. I have three now and they all get used.