A dual-mode electrical plug includes an insulating body formed with a channel and an elongate guiding aperture; a pair of conductive components disposed on the insulating body; a ground prong including a hollow prong body disposed in the channel and movable between an extended position and a retracted position, and the prong body defining a wire containing space, the ground prong further including an operating part disposed on an outer surface of the prong body, the operating part extending through and being movable in the elongate guiding aperture so as to drive movement of the prong body; and a ground wire extending into the wire containing space and including a connecting end for connecting electrically to an inner surface of the prong body.