Question concerning outlet

I was using a simple 3 wire circuit analyzer on the outlets outside the client’s house and all but one were fine. The outlet I am referring to has a switch to turn off the power to the outlet.
With the switch on, I tested the outdoor three prong outlet with the analyzer and it showed it was working properly. When I shut off the power to the outlet with the switch, the analyzer showed only the ground light on. What is this about?
Probably something simple I haven’t thought through.

Typically, indicative of an open ground:

With the switch off, none of the lights should be on if the receptacle and switch is wired correctly. Simply an off circuit, all lights dark.

Hey Brian going to be in your town soon.
How is it there?

Thanks William, I just wrote it up as an outlet that wasn’t wired correctly and referred it to an electrician for a further evaluation.
I still don’t get why they weren’t all dark. It bugs me when I don’t have an answer as to why something like that is going on.

Hi Bob,
I’m glad you asked, I have been reading your posts for some time now and consider it a privilege writing to you.
The weather was fairly hot about a week and a half ago but today we have rain and its a bit chilly. Of course those of us in the San Francisco area haven’t a clue as to what you go through in Chicago.
Mark Twain once said “The coldest winter I ever spent, was a summer in San Francisco”.
Dress accordingly.
Best regards!

Looking forward to visiting in January.
Maybe you can show me a Cal inspection?

January’s are mild compared to most of the nation’s weather. It gets a bit frostier where I live in the East Bay. I’d love to take you on a Cal inspection. Let me know when your in town.

How would the ground be connected when the switch is on but not connected when the switch is off?

What if the switch was wired backwards and the positive is looped and the neutral is switched.

Your guess is probably better than mine…I was simply referring to three light tester indicator light described by the OP.

Get it checked by an electrician , Could be line leakage .Induced voltage ,or other things …
Cannot analyse from a distance needs on site diagnostic .