Mystery Oil leak in tail pipe of my 2000 Ford Explorer

#1

I have a slow drip coming from the last segment of the exhaust pipe of my 2000 Ford Explorer. It seems to be coming from the joint that unites the next to last piece of pipe and the last pipe of the muffler. The fluid looks yellowish (like antifreeze), and feels very much like oil. The oil level in the car is fine. The antifreeze level reservoir is a bit low, but not empty. What fluid can be coming from the muffler? It is definetely not water!