Many people use the wine coolers - set to keep the temp around
65" - places like Fla & Cal get to warm to store cigars safely.
So instead of running the AC all the time, people retro-fix the wine coolers to be humidors.
As for using a regular fridge, they work well.
You need to keep cigars in boxes, the cedar helps hold the humidity.
Above 70" you run the risk of bettles hatching & eating your cigars.
I've seen some really nice fridgadors, some older fridges that were
classic - personally I think a cooler works well unless you have enough space for a fridge.
The cooling system can cause RH problems -
it's tricky to get it right.