You guys are going to hate me, so don't stone me, but........ This is a very common pactice here and other areas. We take a 20 circuit and loop the feeds with #12 at sw's and tap on #14's for sw legs and 3ways in houses and very light small commerial jobs. We also use #14 taps on sw receps, do to the fact that if you are using 15 amp rated devices anyway, you cannot plug in a 20a rated cord end. Also I do not back stab devices.
