Template for cutting holes in drywall for single and double gang old work boxes.

This has a very inexpensive "Johnson Level & Tool 125 Cross Check Level", https://www.amazon.com/dp/B000LDETSU, to aid in getting the template leveled on the wall before marking. Use a bit of super glue to glue it to the template.

Place on wall, level it, mark around the outside perimeter for a double gang box. For a single gang box, mark around the Single section of the template, then use the edge of the template to finish marking the partial line on the one side. Then cut the drywall right on the lines.

I placed some thin adhesive rubber feet on the back to keep it from sliding around on the wall.