The refrigerator pan is usually behind the grill or toe kick on the bottom. If you don't clean it on a regular basis, expect it to be quite gross when you pull it out.

The one you should vacuum every now and then to keep the coils clean and the fridge breathing?

Yeah, there's cooling coils down there, but there should also be a very shallow plastic or something pan that is under the coils and may run most of the depth of the refrigerator. It collects water that drips off the coils, with the intent that the water will evaporate off the pan.

Sometimes it collects faster than it can evaporate (like in the summer humidity) and there's standing water in the pan that starts growing mold in it.

Somebody posted a picture of one here

http://thefullerbrushgirl.com/blog/w...7/drip-pan.jpg

Tearing down the building, hauling off the detritus and sowing the site with a fungidide seems to help.

For those of us residing on or near the Gulf Coast the old maxim may apply....

"Like herpes, when you get mold and mildew, it's forever...."