Follow a step-by-step process: mark the location, drill holes, insert anchors, and secure the box for a weatherproof fit. Apply weatherproof sealant around the box edges and cable entry points to prevent water ingress. Safety remains crucial during installation. Moisture in masonry walls, drilling into dense surfaces, and securing the box on uneven or brittle areas. Learn how to mount octagon electrical boxes in brick walls using several methods. In this article, we'll walk you through the entire process. To install a masonry electrical box for an outlet on a stone wall, start by using a drill driver with a masonry bit to locate suitable spots in the wall. Due to previous treatment, it may be difficult to find mortar joints.