Top Greener Inc via Amazon offers its Top Greener Humidity Sensor Switch for $41.99. Coupon code "6RP6A5TH" knocks it to $29.39. With free shipping, that's $31 off and the lowest price we could find, although we saw it for $4 less in October. It can control both a bathroom fan and light simultaneously. When humidity exceeds a preset level, the switch will automatically turn on the fan. Deal ends December 9.