An electrical safety device is a device that is used to protect electrical circuits from damage due to overcurrent or short-circuiting. The most common type of electrical safety device is the FUSE, which is a device that contains a piece of metal that melts when too much current passes through it, thus breaking the circuit and preventing further damage. Fuses are typically rated in amps, and the correct size FUSE must be used for the application in order to ensure proper protection.