None conservative attitude is observed among the African people in non-conservative utilization of public power supply. Individuals are often observed power on the lightings, cooling systems when not needed at homes, offices and commercial centers. This increases power bills and may hinders a nation from diverting power to industrial areas, limiting the process of industrialization and waste of energy. To avert these, this paper presents development of automatic switch using passive infrared sensor (PIR) and solid state relay (SSR) for day and night detection. The objective of this project is to replace the electromagnetic relays which may fail as a result of carbon forming resulting from arching in existing designs with solid state relay. Also, the system is to conserve energy more by ensuring that bulbs are not powered on during the day time except in cases of darkness. The circuit was designed using components such as; power supply, PIR sensor, Light Dependent resistor (LDR) sensor, Microcontroller and SSR, as showed in the circuit figures 1 and 8. The system is achieved using PIC16f628 which is programmed using Micro-C, SSR for switching, PIR for human detection and LDR to detect night and day. The system was tested and worked perfectly. It helped to conserve energy.