An electromechanical toilet leak detector comprises first and second enclosure portions. An adhesive structure disposed on the second enclosure portion, the adhesive structure in use for being removably adhered to the porcelain outer surface of a flush toilet. One of the first and second enclosure portions includes a groove that mates with a lip provided by the other of the first and second enclosure portions to provide a substantially water-resistant seal therebetween. A vibration sensing transducer disposed between the first and second enclosure portions generates a signal responsive to vibration generated by the toilet due to water inflow turbulence.