The far more likely explanation is that your unifi dashboard's device identification logic is broken and is misreporting the device. Otherwise it doesn't make sense for samsung to engage it a massive conspiracy of putting wifi hardware in non-smart devices (driving up the BOM cost), creating a massive botnet that can share credentials between devices, all so they can... maybe run a residential proxy network? Then subsequently detected by anyone who looks at their device list.

Even if you think they're running some sort of massive botnet, the fridge being part of it is still implausible. They probably have billions of phones and tablets alone, plenty enough to scrape/DDoS the entire internet several times over. There's no need to add clandestine hardware into non-smart fridges.

What model of fridge?! How did you know the random device on your network was your non-smart fridge? This is a wild story. I want to believe but if it's true I think there's no sane solution other than exploratory surgery on every appliance you buy.