The reason for why LED light could flicker or shine dimly even after it has been switched off is as follows:
The main causes of LED glowing or ghosting
1. Switched Neutral (Reversed Wiring)
In home wiring, this is the most frequent reason.
What occurs: Rather of interrupting the Live/Hot wire, the wall switch is configured to interrupt the Neutral wire. The hot wire is still directly attached to the LED driver even when the switch is off. A tiny "phantom voltage" is created by the capacitance between the live wire and the ground/earth wire (or the wall's physical structure).
Effect: LEDs are incredibly efficient; to produce visible light, they only need microamps of electricity.
Fix: To stop the Live/Hot wire, the switch has to be rewired by a certified electrician.
2. Switches with lights or indicators
This is the problem if your wall switch contains a little neon light or LED that shines so you can locate it in the dark.
What occurs: Current must pass through the primary LED bulb to complete the circuit back to neutral in order to power that little indicator light. The primary bulb might light weakly thanks to this modest trickle current.
Fix: Install a snubber capacitor (0.1µF to 0.47µF, X2 safety certified) across the LED fixture terminals to absorb the leakage current, or swap out the switch for a non-illuminated one.
3. Smart Dimmers or Switches (No Neutral Needed)
Wi-Fi, Zigbee, and Z-Wave smart switches require power to remain networked even when the light is "off."
What occurs: The smart switch leaks a tiny amount of operational current through the LED or bulb filament to power its own radio if there is no neutral wire in the switch box. As the driver charges and discharges, this results in either a continuous glow or a sporadic flash.
Fix: Connect an LED Bypass Capacitor/Load Resistor in parallel with the light fixture. These devices are sometimes marketed as "Ghosting Fix" adapters. This avoids the LED chips by giving the current a low-impedance channel.
4. Temporary Afterglow after Capacitor Discharge
What occurs: Filter capacitors are part of the LED bulb's driver circuit. These capacitors store a charge that leaks via the LED chips when the power is interrupted.
Differentiation: This is transient. Over the course of five to thirty seconds, the light will go from dim to dark. Refer to reasons 1-3 if it persists indefinitely.
Reversed wiring (Reason 1) poses a possible safety risk since the light socket stays energised even when you believe the circuit is dead, even though the glow is often harmless to the LED's lifespan. Use a non-contact voltage tester or speak with an electrician if you're not sure. you can see more LED Light knowledge on http://www.benweilight.com
