2017 37TS screeching refrigerator ghost

[Oma/opa]

This past week we were at a campground and running on 50 amp power. The second morning the wife says to me "Did you hear the screeching noise coming from the fridge last night?? I said no and she said well I opened to door then closed it and the sound went away. Thought no more about it until about 1:30AM the next morning when the screeching noise woke me up. Got up, tapped on the fridge door and the sound stopped. Went back to bed and 10 minutes later the same thing started again. This time I turned the fridge off but the sound kept going so I turned it back on. The sound seems louder towards the bottom of the fridge. I don't recall if I heard the fans running or not but decided it must be a fan going bad. Closed the door to the bedroom and went to sleep. Sometime during the night, the sound stopped and never happened again until we got home the next day. We had turned off the fridge and cleaned it out and a little later the wife says the sound started again. Went to check it out and it stopped. Today I accidently found the fans(behind wood baffle in upper vent), don't ask how. To test the fans, I bypassed the temperature switch and turned the fridge on. Fans have been for 2hrs now and are doing fine. By the way, the fridge worked for our whole trip and maintained good temperatures even with the screwed up baffle work by Jayco.
So, can anybody give me a hint as to where my ghost is living so I can shut it up.
Fridge is a Norcold 4 door 121X series