Abstract: A liquid detection method, apparatus, and system are disclosed. In one embodiment, an apparatus includes a non-conductive housing base having an absorbing material to expand on contact with a liquid and a conductive material coupled with the absorbing material to form a closed circuit when the conductive material contacts a conductive surface above the apparatus. The absorbing material may be a sponge material and/or any other material (e.g., a resin, a polymer, a porous material, etc.) having an expansion coefficient sufficient to cause the conductive material to rise when the sponge makes contact with the liquid. The apparatus may be a removable cartridge of a liquid sensing device.