An electrical connector, such as one for receiving a plug, having at least two prongs for insertion into the connector, and having an electrical cable connected to the prongs of the plug and the connector in the usual way, includes a series circuit having an LED. The LED is located within the connector behind a window, and light from the LED provides a visual indication to a user that the connector is connected to a live circuit. The series circuit is located in a module that can be pre-assembled before being located within the connector and, when in the connector, the series circuit is electrically coupled directly to the contacts in the connector by means of spring contacts located in passageways in the module. Indexing means is provided for aligning the LED in the module with the window in the connector to insure that a user can see if the LED is on or off.