I will be connecting a couple of new lights to a recently built porch. I'm pretty sure I have a loop-in system. I am replacing a two gang two way switch with a four gang (The two way switch is for the landing light - the other one way is for downsatairs hall). The odd thing is that I have found a brown cable connecting the two common terminals in the old switch. Does anyone know what this is for and should I carry it on through to the new connections in the four gang switch?