Water had been leaking through return grill. Secondary pan is rusted and in need of replacement. There is no secondary pipe going down into secondary pan or a SS2 float switch in case of primary drain blockage. The secondary pan although rusted out is currently dry with no moisture. Drain line became clogged over the summer and water backed up into unit and made its way through return. Refrigerant pressures are currently good. Cleared drain line. System is working at this time however there are other issues. Condensing unit is rusting through the bottom. Corrosion on coil and rust on compressor and filter drier. Evaporator coil is also rusted. Recommend and put in estimate for secondary pan replacement and install a SS2 float switch.