You should never trust a beep test always read the meter as it will beep way above a good low resistance of less than an ohm. Even this is not fool proof as a meter induces a voltage then measures it at the other end so if you have power connected your get a false reading. Also as the circuit is not loaded you have no current draw you can still get a good reading over a poor circuit . To sum up always load your circuit and check voltages across it this will quickly ascertain if a live,earth or consumer fault. Kind regards Tom