Garage GFCI tripping question

So before I pay hundreds of dollars to a professional electrician to come out, I was hoping to see if I could find a solution/advice here. Here’s the situation:

Like most people, I have a garage fridge . It is plugged into a GFCI. The GFCI keeps failing and the fridge shuts off. We moved in four years ago and the previous family left an old busted refrigerator in the garage that was still working. Fast forward about 3.5 years and it stopped working and the GFCI kept tripping. We assumed it was due to it being a really really old refrigerator because we had had no issues prior to that. So we recently replaced the refrigerator with a new model designed for garages. When they swapped out the refrigerators, a bunch of water spilled out of the bottom of the old one and that’s what made us assume the refrigerator was definitely the issue.

This morning, the GFCI tripped again. I reset it and a couple hours later it tripped again. So now I’m assuming it’s an issue with the box/wiring and not the refrigerator. There is nothing else plugged into that outlet.

Does this sound like a major problem or something that I could possibly fix on my own? I know electrical work can get expensive so if it’s something I can do myself I would prefer that. I’ve replaced outlets in my home before with the help of YouTube and I feel like I’m a pretty good DIYer. But I’m also smart enough to realize when I am in over my head and to just let a professional handle it.

I just don’t want to get snowed by a company and have to pay a $100 assessment fee and then pay god knows what for repairs when it could’ve been a $20 fix on my own.