An electric socket in which the socket body has two outer electric wire supports transversely raised from the two opposite ends of the top wire groove thereof, and an intermediate electric wire support transversely raised from the top wire groove between the positive metal contact plate and the negative metal contact plate, the outer electric wire supports and the intermediate electric wire support having a respective transversely corrugated top edge fitting the transverse cross section of the periphery of the electric wire being mounted in the top wire groove and forced into engagement the periphery of the electric wire to stop rain water from causing an electric short circuit or current leakage.