Old Light Switch Wiring To New

Fix old house wiring problems.

Old light switch wiring to new. In box 1 disconnect a wire on the old switch and attach it to the correct terminal on the new one. I m changing the light switches only to put some new ones on but not sure where the wires from the old switch labelled a a1 b b1 etc should connect to the new switch which just has l l1 and l2. Just black wires and one white wire. Here s how to do it without breaking the plaster and lath.

I bought a new light fixture to replace an old outdated light bar the bathroom of my apartment. Now i suppose the simple question is can i use the above wiring in my new 10amp double 2 way switch and if not what type of switch should i be after. The building was constructed in 1926 so everything is super old. I ve attached a few diagrams of the existing wiring in the hall and living room.

Its a light switch in the hall way its a very old house and the light switching works perfectly well. My father in law is doing some decorating and wanted to update the switch. Bring old light fixtures wired with knob and tube wiring up to code by installing an electrical box in the plaster wall. I have replaced many switches before but never seen one like this without any markings.

Or is it a case of simply swapping over the numbers from the old switch to the new however on the new switch which of the common would have the 2 wires in. Methodically dealing with one wire at a time will help avoid confusion and mistakes.