I did one for my trip last year.

A list was started and the first person arriving was tasked to buy the fridge. Those early in the swap sent the buyer a small amount for the purchase. Swappers connected with those before and after them on the list and were responsible for arranging transfer. Packing tape, pen and paper were left with the fridge in the event that it had to be left with Guest Services. Both my handovers were person to person. We connected over the resort phone system and arranged a convenient time when we arrived/departed.
The key thing is to not have a gap of more than 2 weeks as Guest Servives won't guarantee to keep your box that long. And keep the original box and useful packing material to repackage the fridge as that will lessen the chance of damage.

Hope that helps.