A motion sensor switch is a device that automatically turns lights or appliances on and off based on movement. It uses infrared or ultrasonic technology to detect when someone enters a room or passes by. This feature helps save energy by ensuring that lights are only on when needed. These switches are commonly used in homes, offices, and public spaces for convenience and security. They can be installed in various locations, such as hallways, bathrooms, and outdoor areas. By integrating with smart home systems, motion sensor switches enhance both safety and efficiency in everyday living.