The present invention is directed to a protective shutter assembly for use within a cover assembly of an electrical wiring device. The assembly includes a frameless shutter sub-assembly movable between a closed position and an open position. The frameless shutter sub-assembly is configured to move from the closed position to the open position in response to engaging at least one plug blade having a predetermined plug blade geometry. A spring member is disposed within the frameless shutter sub-assembly. The spring member is configured to bias the frameless shutter sub-assembly in the closed position. At least one retainer element is disposed in the frameless shutter sub-assembly. The at least one retainer element being configured to retain the spring member within the frameless shutter sub-assembly. At least one registration member is disposed on the frameless shutter sub-assembly, the at least one registration member being configured to position and align the protective shutter assembly within the cover assembly.