I don't believe there is anything in the code regarding your intention,
except that the breaker size would have to be reduced to protect the
smallest conductor or 15 amp in your case. IMO it is a poor practice, as
someone in the future can to easily replace the 15 amp breaker with a 20,
not being aware of what you've done
wrote in message
ups.com...
I've got a 20A circuit, #12 wire for the feed the outlets (4 of them).
I would like to add a switch and tap the outlet to feed the light
switch (in a closet).

Is it up to code to use a #14 (either back-stabbed or screwed-on) to
feed the switch? I realized that mixing wire gauges is not always good
practice. However, I've got a lot of left-over #14 that can be used
for the short run.

thanks
rich