2001 996 C4 Foggy rear view mirror

Vehicle Information: Model: 996 C4; Year: 2001; Body Type: Coupe; Total Mileage: 22,000;

My 2001 996 C4 has the autodimming rearveiw mirror, which began to fog over, with just a little in the bottom which remained clear. I also noticed for black tarrish liquid that oozed out from the button at the center of the base of the mirror. Has this happened to any other members, and whats the solution?Thanks