[hharney]

All good comments and warranted likely causes. But don't get hung up on the obvious, it can be a microswitch but it can also just be a bad connection to the microswitch. This system is a daisy chain around the airplane that connects from point to point so it could be any connection along that chain. It is sometimes hard to tell if the connector or connection is bad so take some time and trouble shoot each point. It should be on jacks to do this as you will want to swing the gear to detect the fault. Remember a lot of issues only happen in the air because of vortexes from flying so they may not be duplicated on the jacks.