My house has mostly AC/BX wiring. I have added a light to an existing lighting circuit and pulled #12 Romex into an existing metal box. Problem is, this box has no 1/2" or standard size knockouts. It has only the smaller AC knockouts. I need a snap-in cable clamp to properly ensure my non-metallic insulation doesn't get cut on the metla box opening.
I feel like this would be a nornal request but the folks at home Depot looked at me like I was speaking a different language. I did find some 3/8" push-in cable clamps but they still looked to big.