Abstract: A water leakage detector is disclosed herein sensitive to the presence of moisture, having an elongated sensor strip comprising a pair of conductors separated by insulation. Each conductor includes an electrode coupling with a wire lead extending via a cable to an electrical plug. A circuit housing is provided having an audible alarm operably connected to an electrical socket adapted to detachably connect with the plug. A low voltage battery and auxiliary output socket are carried on the housing and connected with the alarm and the first mentioned socket whereby the presence of moisture across the pair of sensor conductors activates the alarm. A battery test pair of electrodes is provided to manually test battery condition.