drywall
I'm mounting a ceiling fan into an existing ceiling fan electrical box.
The drywall was finished around the box such that it's too close to the box and will be in the way of the hanging bracket and fan trim. I'll need to cut it back. What's the best way to trim back drywall in a situation like this?
My experience says to use the rotary tool, but I have always used metal boxes with plaster rings. I have no experience cutting drywall over plastic boxes. I do have three pointers for cutting with a rotary tool:
If you still don't want to use the rotary tool, there is another option. There are tools that attach to plastic electric boxes. You put them on and then position the drywall where it will be installed. Press the drywall against the tool, and it will place small perforations at the outside corners of the box. Connect the dots and cut. The image below is of one of mine, but I haven't had the chance to use it yet.
A vibrating Multi-Tool (Dremel multimax etc) will work great on this. Mark with a line and cut freehand, you can easily get within 1/8th inch.
Best Answer
I ended up following suggestions from @PlatinumGoose and @Stanwood by extending the electrical box lower using a 2x8 cut to fit, as well as a electrical box extender.