Hi there, first-time poster and first-time homeowner. I thought it would be a fairly easy task to freshen up our half-bath, so I'm doing that as my first project. It had some suboptimal wallpaper and a tired light fixture.

https://imgur.com/a/XyKPQZj

I removed the wallpaper and then removed the light fixture, thinking it'd be best to paint that wall first so I have light for the rest of the project. I switch off fixture, flip the breaker that says it's for the bathroom and... my power-checker-thing says it's still feeding it power. So now I have a wall fixture that's in the way of me stripping wallpaper/painting the wall and I don't know what to do.

https://imgur.com/a/r8Ie3l9

Does anyone have advice? Thank you.

Edit: I've never worked with electricity. Can I do this without hiring an electrician, or should I just bring one out here?