My 1987 house has a CH 100 amp main service panel (22 spaces/22 circuits). I want to add an Eaton Ch Series 1-Pole Twin Breaker 2 - 20A for a garage circuit. Ground bus is full (with one lug already double-wired-not my doing). Plenty of spaces available in neutral bus.
Question is, in this main panel, can I double-lug the ground from the yet to be installed 20a twin breaker to the existing fully loaded ground bus? Thank you for whatever advice you can give me on this.