I'm working in an older apartment complex built in the early 1970's that has aluminum wiring on all of the originally installed light switches I can not find an AL / CU rating. ( they are Leviton )
There are some markings such as, the letter A circled but not much else other than Spec Grade, UL Listed.
The originally installed receptacle outlets do have a CU / AL marking on the screws.
How can I prove that the originally installed light switches are rated for AL wiring?
The switches should have co/alr written on them somewhere.
Switches and outlets made for aluminum wiring usually have dull screws while devices for copper wire usually have shiny screws.
It may be the switches are not for aluminum.