I was redoing some electrical in my basement and was wrestling with how to handle the receptacle for the sump pump (there is a debate as to the safety/practicality trade-off for using a GFCI/standard receptacle). The win-win solution I arrived at was a GFCI with a built in alarm that will sound, when tripped, until the receptacle is reset. I used this one from Leviton and it has worked great thus far. Obviously the alarm won’t work in the event of a power outage, but otherwise I will hear continuous alarm pitch until the outlet is reset.
I just though of something else as well. They make GFCI's that will alarm, so you can potentially use that to alert you to an issue.
https://www.amazon.com/Leviton-GFTA2-W-SmartlockPro-Self-Test-Audible/dp/B01CD4XUIE