Thank you for your suggestion. I had photographed it earlier, in case my local RV dealer had one in stock. However, I went a bit further following my post and exposed the wires in the back so that we would know which switch, and I discovered that the "double" switch is, in reality, two "single" switches. Since I had a single switch just above it that we've never used (to an outside light that's been burned out), I just switched them and all is good for now. Until the next problem...