Four different combinations of a sliding internal shutter and shutter lock control mechanism are described along with methods of incorporating the combinations into receptacles to prevent foreign objects from gaining access to power. Each combination is composed of a ramped shutter, spring biased in a closed position, and two to four lock control mechanisms, each of which moves a locking bar out of contact with an impeding surface on the shutter. The entrance of a standard plug into the assembled receptacle moves all the locking bars away from the shutter's impeding surfaces and the blades interaction with the ramps moves the shutter to the open position allowing the blades to continue to power. The combinations may be installed in receptacles as standalone modules that are installed in a receptacle case or the parts may be integrated directly into a receptacle structure with the proper support structure. These four shutter-lock control mechanism combinations provide superior safety and do not suffer the rejection problem common to the present tamper resistant receptacles. Another three shutters that open by rotary action when the lock control mechanism is in the unlocked state are presented. The safeties of these are similar to the present tamper resistant receptacles but do not have the rejection problem. A method is also provided.