A wireless control device may include a housing, a yoke, an antenna, a communication circuit, and a control circuit. The yoke may be electrically conductive and be configured to mount the wireless control device to an electrical wallbox. The antenna may be configured to transmit and receive radio frequency signals. The antenna may be a slot antenna. The communication circuit may be configured to transmit and receive the radio-frequency signals via the antenna, and the control circuit may be responsive to the communication circuit (e.g., the signals received via the communication circuit). The control device may also include a conductive component that is attached to a front surface of the housing. For example, the conductive component may be electrically connected to the yoke via a single electrical connection (e.g., a screw). Further, the conductive component may be parallel with the antenna and configured to be capacitively coupled to the antenna.