Up until yesterday, the audio on my wired doorbell was fine. Today it sounds like it’s positioned near a fishing river. There’s no wind and no activity and all the sudden it’s just lots of noise. Is there something I can check for the cause?
I had that happen before! It may sound funny but more than likely water has gotten into the speaker or mic. All I did was take a hair dryer and blow on it for a few minutes but that is with it removed. I hope this helps. 
I left it for a day and the noise went away. We didn’t have any rain for over a week, so I know it wasn’t a moisture issue. Weird.