Replace on-off light switches in RV - any cheaper choices

My problem with the paddle switches that had to replace the Cole Hersee is they were switched OFF but when I slid the lever forward on the battery disconnect I would find odd lights burning and the switches did not shut them off. Another manifestation of living where the salt laden humidity never requires more than a sheet at dawn on a bed. When I started misting the rose bushes in the morning they took off growing like they had a rocket strapped to them. Salt on the leaves. Ugh.