It is not possible to equip a 4 way switch with a pilot light.
The 3 way switches at the ends of the traveler run of a 4 way setup can be equipped with inverse pilot lights (night lights) where the switch is lit when the light controlled by the switches is off. There are some limitations on the kind of light bulb for the light being controlled, notably the switches might not light up when you use low wattage compact fluorescents.
The 3 way switches at the ends of the traveler run of a 4 way setup can be equipped with inverse pilot lights (night lights) where the switch is lit when the light controlled by the switches is off. There are some limitations on the kind of light bulb for the light being controlled, notably the switches might not light up when you use low wattage compact fluorescents.