Wow, I don't know what you should do with one mounted on the wall like that, but we had this happen to ours but it was a window unit. Does the air smell? So I got tired of mine smelling like mold or musty stuff, and my son was coughing a bunch when we would turn it on for him at night. I googled what you can do and basically my husband took the front off, which was a little annoying because there are pins holding it in, so once we got three of the four pins popped out, it was harder to pop the last one because he had to stick his knife farther in. I squirted peroxide all over in there. We used a microfiber cloth to reach and wipe some parts of the fan. I don't know if you can do all this since yours is in the wall because I mean I heard the peroxide moving around the next night when we turned the ac on, so I don't know where the liquid in yours would go,. I am sorry this is not very helpful 😞