The best method to wire shielded cables for screening is to ground the shield at both ends of the cable. Traditionally there existed a rule of thumb to ground the shield at one end only to avoid ground loops.For more, see electromagnetic interference). The shield minimizes capacitively coupled noise from other electrical sources. The shield must be applied across cable splices. In shielded signal cables the shield may act as the return path for the signal, or may act as screening only.