Ground fault circut breaker

[Poprivet]

My frig stopped working on A/C and during trouble shooting, found the bath area plug not working. I plugged the frig into another circuit and it works fine.
I then got out my trusty voltage tester and got voltage at both outlets. I don't know how much as the tester is a go - no-go lite and not a meter. If I open the ground fault circuit breaker, I lose the voltage on the tester. I then used my vacuum cleaner has a load and it would not run when plugged into either of the ground fault circuits even though the tester indicated voltage. I suspect a faulty ground fault circuit breaker?? ///any ideas?
I also discovered the out door receptacle is not on a ground fault circuit.

[Rebee]

A meter will tell you how much voltage you have. You may have enough to "light" the tester light, but not enough to run the frig. A low voltage condition may need some professional help.

I would get another Gnd fault outlet and see if you get same results.