A tilt sensor for a cleaning device makes use of an optical sensor to interrupt operation of the device. In one implementation, the tilt sensor shuts off a UV light included in the cleaning device's operations. The tilt sensor includes a housing with at least one chamber defined therein. A sliding or moving element is located in the chamber. The optical sensor is operatively associated with the chamber so that, in response to certain movement of the element within the chamber, the optical sensor signals the tilt sensor to turn off the UV light.