For how long? LEDs produce broad-spectrum light using phosphorescence activated by discrete-spectrum light. Those phosphors will glow for a few seconds after you turn them off, or if you're really sensitive you may see a glow-in-the-dark phenomenon. When you unplug a lamp or turn off a true switch, there should be no residual current.
If you are using the bulb itself to adjust the power level, like with some smart bulbs that you are supposed to leave switched on, it's possible that they never turn off the power completely for some reason. LEDs are dimmed using PWM so they may have an off setting that is like 1% of duty cycle or something, who knows.
If you are using the bulb itself to adjust the power level, like with some smart bulbs that you are supposed to leave switched on, it's possible that they never turn off the power completely for some reason. LEDs are dimmed using PWM so they may have an off setting that is like 1% of duty cycle or something, who knows.