Volt stick sound ac voltage detector volt stick voltstick sound this volt stick device is a handy tester that is easy to use it will detect the presence of an ac voltage without the need for the disconnection of cables fuses circuit breakers etc br br the red indicator in the tip illuminates on detection of ac when the tip is close to any live point or is moved along any insulated cable br br the detector features a buzzer for assistance in conditions such as bright daylight an