75gmck25
Well-known member
Its not an elegant solution, but I might hold the box steady with pliers and drill a large hole through the existing plastic box, stick a sawzall blade through it, and cut the box in both directions until a large piece comes out. Then use that hole to access the plastic plate/ears and also cut them off the box. If its plastic you should be able to carefully break it out in pieces and end up with a fairly clean hole.
On the side where you have the plastic ears screwed to the joist you will also have a joist above the drywall, so any patching will be supported and easy to apply.
I've used this general process to cut a few old metal boxes out of plaster, so I don't think it would be any harder with drywall. The biggest challenge with plaster is that its so inflexible that it breaks instead of flexing. I had to make sure I was holding the box firmly with the pliers so it did not vibrate against the plaster while I was cutting.
Bruce
On the side where you have the plastic ears screwed to the joist you will also have a joist above the drywall, so any patching will be supported and easy to apply.
I've used this general process to cut a few old metal boxes out of plaster, so I don't think it would be any harder with drywall. The biggest challenge with plaster is that its so inflexible that it breaks instead of flexing. I had to make sure I was holding the box firmly with the pliers so it did not vibrate against the plaster while I was cutting.
Bruce