A method of extending RF signals in a wireless control system which includes a first electronic device, a second electronic device, and an RF signal extender. RF signal coverage areas of the electronic devices partially overlap, and each of the electronic devices is out of the RF signal coverage area of the other one. The RF signal extender is in an overlapping area between the RF signal coverage areas, and the electronic devices are in an RF signal coverage area of the RF signal extender. The method includes the steps of: receiving an RF signal with the RF signal extender; analyzing the received RF signal to retrieve the data carried therein; and compiling the data into an RF signal for transmission if the retrieved data follows an RF communication protocol of the wireless control system. Whereby, a total RF signal coverage area can be expanded, and interferences can be reduced.