Abstract: The apparatus is a combination smoke and water detector. The smoke detector has an alarm and a test switch. The smoke detector is electrically connected to an open cell foam sensing pad through a pair of wire leads. The sensing pad is contained in a plastic housing having at least one water inlet hole. When the sensing pad is wetted with water, the pad becomes electrically conductive, by-passing the test switch and activating the alarm on the smoke detector. The apparatus is particularly suitable for detecting leaks.