If there is a sparky around, can you tell please why this "Long Life" bulb when switched off for hrs, sometimes a day or two, it keeps flashing very faintly every 1o-15 secs ?
You mean one of the 'energy-saver' compact fluorescents or a filament bulb? Fluorescent tubes can light up if you put them near a powerful RF transmitter or high-frequency, high-voltage coil. But if it's flashing when it's supposed to be off, you more likely have a fault on the wiring; sounds like the switch is either dodgy or is maybe it's switching the neutral wire instead of the live. Moving to SteveyG. He's quite sparky.
We'll have to wait until we know if it's an incandescent or fluorescent lamp. Does it stop flashing after it's been on for a while? Does another bulb in the same lamp holder do the same? Flickering on fluorescent type lamps is usually either down to the tube nearing it's end of life, or the ignitor/ballast circuitry being up the duff!
I'snt there mercury in fluorescent tubes? Isn't that what made the hatter mad? Perhaps there is a leak I sometimes see flashes out of the corner of my eye, but I just attribute that to Ken Kesey.
the wiring crossed bettween L & N is a good thought, I'LLcheck both ends, bulb & S/W. Looks like 10-15mm x 40mm 6 tubes in 3 pairs. Thanks all.
That's a compact fluorescent, aka Energy Saver. See here for explanations (Ian Stirling in particular), but as they suggest it's possibly slight (harmless) leakage charging up a capacitor to the 'fire' level, firing produces a brief flash of light, flattens the cap and the cycle starts over. Electricians' neon screwdrivers also can give false positives, lighting up even if a circuit is switched off if there's very slight leakage.
