I am going through my house I just purchased that was built in the 1950s and replacing all of the light switches as the old ones are faded and quite unsightly. I noticed when I pulled out my first switch that it only has two terminals and is missing a ground terminal; however, there is bare copper wire in the electrical box along with a neutral wire. The copper wire is coming out of the same bundle of wires entering the box as show in the picture below. Pictures attached below
So my question is now that I am installing new switches that contain a ground terminal, should I use that bare copper wire as ground? Or is that possibly used to ground the electrical box, for the fan, or something else down the line? Thanks!