Leak from back of engine, leaking into the exhaust manifold.

I have a 1996 trooper this I recently picked up. I noticed a small faint white smoke followed by a burning rubber smell coming from underneath the hood. I saw that it's a very slow drip leaking onto the top of the exhaust which causes the small and smoke. The truck runs fine, no overheating, no other leaks, nothing. It's solid with 242,233 miles roughly. Any thoughts?
PS not an exhaust leak!!!