transfer case shifts on its own

What is your question?

When I turn the ignition switch on I never know what the indicator lights on the 4WD will be on. Sometimes 4LO, sometimes 4HI, maybe Neutral. I don't think it actually shifts, it just doesn't know where its at. Then when I try to shift to where it should be (2HI, usually) most times it works but occasionally it doesn't. Is this the encoder or could it be the control module.