A moisture sensor system is described. In one embodiment, the system provides an adjustable threshold level for the sensed moisture level. The adjustable threshold allows the moisture sensor to adjust to ambient conditions, aging of components, and other operational variations while still providing a relatively sensitive detection capability. In one embodiment, the adjustable threshold moisture sensor is used in an intelligent sensor system that includes one or more intelligent sensor units and a base unit that can communicate with the moisture sensor units. When one or more of the moisture sensor units detects a excess moisture the moisture sensor unit communicates with the base unit and provides data regarding the moisture condition. The base unit can contact a supervisor or other responsible person by a plurality of techniques, such as, telephone, pager, cellular telephone, Internet (and/or local area network), etc. In one embodiment, one or more wireless repeaters are used between the moisture sensor units and the base unit to extend the range of the system and to allow the base unit to communicate with a larger number of sensors.