Wiring – Do I need to cover an unused punched out hole in a junction box? If so, how

junction-boxwiring

I removed a Romex cable that was going into a junction box top middle opening(you can see in the picture).

There is still an opening at that punch out.

Is it okay to leave it as is? If not, how do I cover it?

junction box

Best Answer

A "knockout fill plug" - costs a few cents (depending on supplier - some are over a buck, I'd keep shopping), snaps into the hole (take the clamp out first.)

knockout fill plug knockout fill plug