Hansel, can you show your scheme how to make it? I have no very good skills in it but I try to improve it that’s why I want to clarify to myself how it should be. I have never heard about handmade aux switches before and as usually order it via internet like this page http://hardware.nl/hulpschakelaar/siemens but last time it became very expensive so I think I can do it by myself and also quality will be better then any purchase