Performed for maintenance on mini split system. Including clearing drain line. Washing outdoor coil. Cleaning indoor filters and surfaces. Inspecting system operations and refrigerant levels. Added a small amount of pipe to the outdoor drain so that condensate doesn’t run onto copper lineset. No cleaning chemicals used because of birds. As for the damp wall on the opposite side of the indoor cooling head. At this time technician believes that it was the result of a partially clogged drain line. With drain line completely clear wall should dry and not the damp. If the dampness does not go away and dry up after a week or two technician would recommend removing damp sheet rock gently and looking to see if something is not insulated or and or also using expanding foam to seal all penetrations from conditioned space.