My home was built in 1936. The electrical box is an adaptation of the old screw in fuses to breakers with the main in the box. The box is two phase. The room with the outlet has another outlet on the side of the room and one light with a light switch. There is plenty of room in the attic and the romex is visiable and all wires cnabe seen and traced in the attic. Another words, two outlets, on light and a switch.

Remove the outlet and check all wiring connections. Check for voltage between the hot and the neutral. If you have voltage replace the outlet. If you do not have voltage check connections at the other outlet, the switch and the light. If the outlets and the light are on the same circuit, power probably comes from the light.