... If the wire is Romex,and the old box is metal,you can substitute the box with a plastic cut-in,because they're usually a tad bit larger,and you can cut the wallboard open in order for the plaster ears to be snug against the wall material,..then tighten the hold down screws with the wing brackets and you're done..Available in single,2-gang,3-gang as well..Plastic boxes allow more volume capacity,as there's no clamp for de-rating..
Russ

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[This message has been edited by Attic Rat (edited 05-16-2004).]

.."if it ain't fixed,don't break it...call a Licensed Electrician"