See if there is a tray underneath the whole thing that collects water drips. It is built in on most fridge/freezers, and is a small hose that runs down from the freezer to the tray, for when the freezer automatically defrosts. It drains into that tray, and can get really funky if left long enough. If that is what it is, empty the tray and wash it really well. I put some Pine Sol in it, so that each time a drip lands in it, it smells the kitchen like pins sol.