How to safely install wall-mounted electrical boxes

How to place a solid wall base for beginners
Use water to clean chiseled cut locations
Use 100% cement mortar, do not use masonry mortar or bowl to fix the wall base
Put the glue on the back of the base, don't put the base in first and then add the glue
Determine the elevation by cutting the wall at the bottom of the base
Align the base so that it is level with the wall and should not be convex or concave.
You should place the base after painting the wall for the most accuracy.