An electrical receptacle for selectively receiving two prong polarized or three prong grounded electrical plugs while excluding non-polarized plugs and other foreign materials from being inserted into the receptacle apertures. The receptacle is provided with a body having an internal cavity containing an aperture shield and a locking bar. The aperture shield is biased to the closed position obstructing the receptacle aperture and is retained in the closed position by the locking bar. The locking bar shifts to the unlocked position upon the insertion of the polarized plug or a ground prong enabling the aperture shield to shift transversely to the open position in response to plug insertion.
