Maytag Dehumidfier?

There is usually a float that is attached to the machine that will float in the water collection pail inside. When this float moves up as water from the dehumidifier is working, it will turn off your machine so you don't have water running on your floor. Make sure this float embly is not stuck in the up position. If it is, reach in and gently pull it down so it rests in the water collection bucket. That should turn off your light, and make the unit work.