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Two new lightbulbs(energy efficient spiral) blink rapidly when I turn OFF the switch for the 3 bulb fixture in my kitchen. House built in 1912ish. My house but previously had tenants. They only had 1 bulb in, so probably occurred for them, too. I'm worried about turning it out now. Wiring internally, probably wasn't updated since 1940's , when house converted to duplex.

  • 1940 wiring? With no offense, I would hesitate entering such a place, not to speak about living there or touching anything metal. – yo' Mar 30 '16 at 7:28
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    @yo' That's completely inconsistent with reality. – Carl Witthoft Mar 30 '16 at 13:25
  • @CarlWitthoft Well, that probably depends on the location, I'm quite sure I haven't been to such a place in ages. – yo' Mar 30 '16 at 13:43
  • ?? is there an incandescent in the fixture as well? If so, possible back-EMF – Carl Witthoft Mar 30 '16 at 14:16
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Is your light fixture is controlled by a dimmer switch? If so, it might not be capable of properly dimming the more efficient light bulbs.

I had a ceiling light fixture on a dimmer switch. When I changed from incandescent bulbs to LEDs, the light would blink with the switch turned off. Not dimmed, off. I replaced the dimmer with a simple on/off switch and it works as expected now.

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I would suspect you have a bad switch. Try replacing it and see if that cures your problem.

The age of your wiring is fine. The lifespan of the insulation on your wiring from the 40's should be good for several more decades if it has seen normal use. Insulation gets degraded from overloading circuits that causes extra heat in the wire. Normal lighting circuits are very lightly loaded. It is the receptacle circuits that would fail first.

Good luck!

  • I think the only problem with 1940 -- or 1912 -- wiring is that it probably is 2-wire, so you need to come up with a way to provide grounds. – Carl Witthoft Mar 30 '16 at 13:26
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There may be enough current from the capacitive coupling in the the wires to allow the bulb to flash. This is more likely with a fixture where the power is fed into the fixture and long wires run off to the switch.

Your best bet may be to try another type of bulb (another brand or LED bulb).

There are better electronic solutions, but the compliance with code may not be acceptable.

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Fluorescents are able to be powered by electomagnetic fields... not sure if that is happening here, but it is possible. Tesla actually created fluorescents to be powered without wires. Perhaps some old wiring in the house doesn't have insulation or the insulation is poor; or maybe the house is located near some larger power lines (outside).

enter image description here

Another possibility (if you have an illuminated wall switch): When an illuminated switch is off, the (CFL) bulb is the neutral for the light of the wall switch, causing a tiny current to flow through the CFL bulb. The solution is to solder/install a bleeder resistor to the cfl.

enter image description here

  • Nikola Telsa did that by using 15,000+ Hz AC fields. 60 (or 50) Hz at anything over several meters is not likely to affect much of anything. – wallyk Mar 30 '16 at 17:53
  • Or by radio or walkie talkie: youtube.com/watch?v=lKatgq9sjj8 . That was Tesla's intention – Ben Welborn Mar 30 '16 at 20:23

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