Electrical Questions? Ask an Electrician Online.
Hello. Welcome to Just Answer.
You are correct, in that removing the black or the red should be your first step in trying to get the switch working properly again.
I would try capping the red by itself first. If that doesn't work, reconnect it to the light, and cap the black by itself.
Please let me know how it works out.
OK. Can you pull the wall switch out of the box, leaving all wires connected, and post a photo here, showing all wires?
Thank you for posting the photo. If you take the yellow wire off of the switch in question (with the switch turned off), does the light go out (when it is constantly on and the switch doesn't seem to control it)?
You are most welcome. I appreciate the opportunity to help. Please consider rating my service before logging off. Have a blessed day.