A non-contact voltage tester is a handy tool used to detect the presence of voltage in electrical wires and devices without making direct contact. It typically features a sensor that lights up or beeps when it comes near a live wire, making it a safe option for checking electrical systems. These testers are commonly used by electricians and DIY enthusiasts to ensure safety before working on electrical circuits. These devices are designed to identify alternating current (AC) voltage, which is commonly found in household wiring. Non-contact voltage testers are portable, easy to use, and often come with features like adjustable sensitivity and built-in flashlights. They are essential for anyone working with electricity, helping to prevent accidents and ensure proper safety measures are taken.