The residential fridge in our Legacy came with a long machine screw with a black plastic knob. There is a tapped hole for it located in the metal strip between the fridge and freezer sections. You're supposed to just screw it in and go, but ours still came open. I bought a rubber washer at Lowe's (3/16 x 1-1/2 x 1/8), slipped it on the shaft under the knob and that did the trick.
2015 Legacy SR340 360RB
2014 Jeep Wrangler Unlimited Toad
Gigi, Poppy and Sadie Lady...On the road, but not full time!