Heh, the fridge story reminds me of a guy who got work with a morgue as one of their retrieval/clean up guys and posted some stories of the more notable incidents over on giantitp a few years ago. Sadly that thread got locked after a few weeks when people started posting photos of decay and injuries and things when sharing their own stories, it was quite interesting before that.
Basically the guy's job was to go to places with dead bodies and collect them. Him, a partner and a van with the appropriate bits for handling corpses. Picked up people who died in their beds, in accidents or in criminal cases, then took them to a morgue and did the basic clean up required before sticking them in a cooler and signing them off. That fridge sounds like what happened with a few of the advanced decomp cases he described.
One of the stories he shared was his first case of advanced decomp. Person who lived alone, elderly I think, died and no one noticed until the smell disturbed the neighbours enough to call it in. House carpeted with dead flies, body so rotten it had oozed into the mattress it was on and partway across the floor. Skin sloughed off when he and his colleague tried to move it into a body bag. Real gross stuff. Brown/black ooze everywhere, more maggots wriggling about in places and parts of the bed rotting because of the damp sludge that was left sitting on it.
They had to put the body, and the bedsheet that had become attached to it into the bag, then put the skin and other bits that had fallen off into another body bag, then walk back out carrying what was basically mushy human soup over a floor that crunched as they walked on it because it was such a fly graveyard.
The original telling was better, but sadly I think those tales have been lost to the sands of time.
Anyway, I'd suggest drenching it in a few buckets of diluted bleach, hosing it down extremely well, preferably with a powerhose while wearing eye and mouth protection to avoid getting any rotten gunk in your soft tissues where it can get you sick. Then haul the thing to a dump that can dispose of it properly. If the bulk of the insides is covered in contaminants it's more effort than it's worth to clean it to the point it's not going to smell and be a biohazard, so a courtesy wash for the poor saps who need to break it down and drain the coolant and then a heave ho into the trash heap is probably the best plan.
In concurrence with everyone else though, do not set fire to a fridge with coolant in it. There might be a risk of a pressure explosion from it since coolant boils easily, and shrapnel is unpleasant, but I'm not sure of the pressure the coolant is normally under and what the pipes can withstand. Coolant should be properly disposed of, it's just a good habit to have, though it's not particularly toxic these days and modern coolant is not as big an environmental hazard as the freon stuff was.