An add-on smart controller for an LED lighting device includes a power input port, a power output port, a housing, a control unit in the housing, and at least one control signal receiver in the control unit. A power input of the control unit is connected to the power input port. A power output of the control unit is connected to the power output port. The control signal receiver is configured to receive external control signals. The control unit is configured to activate the power output port to supply output voltage responsive to the control unit receiving an ON signal. The control unit is configured to deactivate the power output port responsive to the control unit receiving an OFF signal.