If you are using APM no need anything other than relay to control lights, read this to integrate relay to APM http://copter.ardupilot.com/wiki/common-relay/

APM yet to come

parichay give me one day time, I ve a relay board but its having a 12v relay, I had another 5v relay as well but I need to find it. I am a lill busy today maybe I ll find search it at evening. once I get it I ll test it over my tx n rx n if it works fine I ll send it to u. please hold on for one day.

sure sure, thanks again