I'm debugging an issue with flickering lights in a house with older wiring (1950s, braided sheath, two wire, no grounding).
I have a lamp with a solid state switch (touch lamp) and LED bulb inserted. I also have a white noise machine plugged in to the same 2-prong outlet. Flipping the the rocker switch on the white noise machine creates a momentary flash of light on the LED bulb when the lamp is off.
I called an electrician and he said it was likely just the LED bulb being sensitive.
I believe I'm okay from a safety perspective:
- another lamp with a cradle switch does not flicker (i.e. there is no arcing, and only lights with solid state switches are leaking current)
- nothing is warm to the touch and there are no smells.
But I'm curious and confused why this is happening. It does not happen in the part of my house with newer wiring. I took an oscilloscope to the outlet and see momentary voltage spikes up to 50V on the neutral wire when toggling the white noise machine. When I hooked up the lamp to the neutral from a different circuit it does not flicker (though I forgot to test the case where Hot is on the other circuit and Neutral is on the suspect circuit).
What is going on here? Is this due to lack of grounding in the outlets? Is this high impedance in the wiring?