wireing ?

Ok i think i know how to do this but not for sure. first i had this idea for my brother who got pulled over for his green turn signals and i think i might do it also. Can i just wire a on-off-on switch to my power wire that go to my turn signals and then wire it up to the normal turning lights and also up to some leds that i would put in or can't i do it that way. my lights i would only need 2 leds in each on because they are very small but my brother would need more in each.