Buckeyegal, our temp sensor (thermistor) also fell out of the plastic sleeve and we had everything freezing in the refrigerator our last trip.
We were not familiar with how the refrigerator temperatures were actually controlled
so we didn't realize that the thermistor had fallen out of the sleeve until we got home and talked to a RV repair guy on the phone. The best I can tell from a couple of YouTube videos is the bulb goes mid-way into the plastic sleeve. I intend to put a tiny bit of silicone on mine, enough to make it sticky, and then put it back into the sleeve to prevent future issues. As lowering it on the aluminum fin is a warmer setting, we had previously struggled to keep the refrigerator cold enough when it was about to fall out, then it fell out, and now everything froze. One extreme to the other, but easy fix. Good luck!
D_B Travelers - 30 nights in 2016... so far. 54 nights in 2015. 2014 Rockwood Windjammer 3001W Diamond Pkg, 2015 GMC 3500HD CC DRW Duramax, Equalizer 14K hitch, TST 507rv TPMS.
"Happiness? A good meal, a good cigar and a good woman - or a bad woman; it depends on how much happiness you can handle."
George Burns (1896 – 1996)