In this paper we propose a design using both a microprocessor and light sensors for automatic room light detection and control. Our design, the HLCM (home light control module) which will be installed in every light fixture of a family, is made up of four blocks: the pyroelectric infrared (PIR) sensor circuit, the light sensor circuit, the microprocessor and the RF module. By using the PIR sensor circuit, the HLCM detects if a human body enters the detection area or not. If there is no human body present, all controlled lights are turned off. If there is, the HLCM detects the light intensity under the environment and maintains sufficient light by controlling the number of lights. We have also integrated an RF module to transmit and receive the data from each HLCM so we can control different lights in different regions. The result of using the HLCM shows that the total power consumption can be reduced.