Once you have a hole, get a decently sized bit (I find 1/4" works well here in both girth and length), put it into the hole you made, and carefully ream the hole out. The thinner knockouts will put up little resistance, but the main box won't let the bit ream it. A "knock out" or "KO" is a partially stamped opening in electrical enclosures that allows quick entry of a wire, cable or pipe via connector or fitting to the interior. With the right information and technique, you should be able to remove a "KO" from electrical panels and other electrical. A plastic electrical box —sometimes called a PVC junction box —comes with small, thin discs called knockouts. These are designed to be removed so wires can pass through. A stripped screw or screw opening at an electrical box is more than annoying, it's unsafe as the device will not be mounted safely and securely to the. I need to re-wire a receptacle and hope to do it without replacing the box or cutting open the wall. I have what looks like a 1995 Bakelite 20. single gang box with no knockouts, nailed to the stud.
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