Odor can it be freon leak?

Two possible causes of odor on fridges:

* Freon Leak
* Defrost Drain Pan dirty.

If the fridge was unplugged for a while or there was a liquid dropped in the refrigerator, it's more likely to be the drain pan. It is located at the back of the appliance, above the compressor.

If it is clean and the smell is not coming from there, then you may suspect about the freon leak.