A device for detecting household conditions and events includes a power supply portion and a plurality of portions able to detect different conditions, or changes in different conditions. Each detecting portion includes an input port and an output port, the output port of one detecting portion is detachably electronically connected to the power supply portion, and the input port of one detecting portion is detachably electronically connected to the output port in a modular fashion of another detecting portion, the remote selection of a specific required detection is also provided.