A word of warning regarding drilling into a refrigerator: some use the discharge line from the compressor to go around the door jam instead of an electric mullion heater to keep frost from building up around the door frame. I'm not sure, but I think the line is fed from the bottom. I'm not sure exactly where the piping feed and return is, but I've seen a lot of residential and small commercial units that get drilled into by custodians to install padlocks and ruin a perfectly good box where I used to work. Tin knockers called me and said they did this and heard a hissing sound. I told them throw the thing into the dumpster. You ruined it! (I did fix a couple with success, but they were for OUR office, etc.!)