Have you looked into an rc switch that you can run in parallel with another channel? There is an optically isolated switch that you can run off a "Y" harness lets say off of your gear channel that will allow you to turn on a landing light when the gear comes down and off when the gear comes up. you can use these swithces to "close" or "open" anywhere during the channels movements. I use mine for landing light and also another for onboard glow driver at low throttle settings due to the fact my engine is mounted inverted. Makes starting and low speed flying easy and without the fear of dead sticking it.