RG58/59 coaxial cable is generally used for low-power signal and RF connections, not for high-power applications. While it can handle a certain amount of power (up to 500 watts for HF frequencies, according to Shure, or 300V, according to Wikipedia), it's not designed for carrying significant electrical power. Exceeding its power handling capabilities can lead to overheating, melting of the conductors, and potentially damage the cable and connected equipment