Normally this will not happen, however some complex circuit systems can cause this instance to occur. This issue happens across the board with different manufacturers sometimes. Possible solutions here include:It is possible that some residual voltage on the line is triggering the light bulb to remain on. Incandescent bulbs do not have this issue, as it takes more power to illuminate them. LEDs use less power and can trigger with less input. You can potentially solve this issue by plugging in multiple lights to the same circuit (within stated limits of the circuit). Some residual voltage could be absorbed that way. If you experience the same issue after implementing the suggested fix, please consult a qualified electrician for additional solutions.You may have an issue within the electrical circuits. Please consult a qualified electrician.