Good Afternoon,
This maybe obvious to the more qualified of you. I was changing the twin switch in the hall. As usual it is for the hall and the landing. The landing switch is connected to the upstairs switch in the normal way, com to com L1 to L1 L2 to L2. However there is a wire connecting the com to L2 on the hall light switch. I cannot see this on any wiring diagram. It doesn't seem to be correct although both switches work and it has be like this for a long time. Any comments?
Rgds Andrew