Line fault at the outlet -- do I need an electrician?


Yesterday, I got a Panamax, Max 1500 surge protector and line conditioner. (I got a very good deal on it, and am just trying it out.)

I plugged it into an outlet I've been using for a while and one of the red lights on the front lit up saying "line fault." (I'm not sure how this is different from a "ground fault." Maybe it's the same.) The Panamax does not do this with other outlets in the room. They seem ok.

So, I know this means that the outlet is improperly wired. My question is, might this be a simple thing to check and/or fix? Any suggestions most appreciated. It's the only outlet I can use to have my audio set up where I usually have it. Now is not an optimal time to call an electrician. If this is a big problem, I'll try out my gear somewhere else in the room, but if I can fix this without too much expertise, that would be ideal.
128x128hilde45
Your wires are reversed in the circuit somewhere you need to take some plates off and start looking at the wires.

Reversed hot and neutral wires. Measuring hot-to-neutral voltage by itself doesn’t tell you if those wires are reversed. You must measure neutral-to-ground or hot-to-ground voltage. If the neutral-to-ground is 120V and the hot-to-ground is a few volts or less, then the hot and neutral wires are reversed


https://www.ecmweb.com/content/article/20900908/diagnosing-power-problems-at-the-receptacle
I'm somewhat perplexed by the latest measurements, and I can't readily envision a miswire (or even multiple miswires, perhaps at the panel as well as at one or more of the outlets) that could account for these findings.  But what I would say at this point, given the possibility of multiple unknown miswires, is DO NOT ASSUME THAT TURNING OFF THE BREAKER WILL KILL THE ELECTRICITY TO THE OUTLET.  

Best,
-- Al

I always use a little light tester in the receptacle or the screws on the side even after throwing the breaker.
Thanks Al. Your use of all caps is exactly what they were meant for.

I won't open an outlet until I'm 110% sure it's off. After all, I've pledged my life to the COVID virus; I can't cheat it by electrocuting myself. (Please pardon the gallows humor. It's all I've got left, except for an obsession with audio.)