Sometimes I don’t want to see my wife’s shared calendar, and sometimes I want. It’s tedious to use the mouse to check and uncheck the box.
AFAIK there are no built in shortcuts for this in the app itself, but I guess I can do this with Apple Script, hence I could use Keyboard Maestro for this task.
Any idea how that AppleScript would look? 
While we are at the subject; One of the reasons I don’t want to see her calendar is that it’s in the way when I want to create new events. Is there a key combination you can hold down while creating an event, regardless of existitng events? (if you press down the mouse on an existing event, you just mark and try to drag it.)