A self-cutting, self-seating, self-securing electrical device is used for mounting lights and devices. It can be provided as an integral one piece box, with a saw ring blade provided as part of the round electrical work box, or the device can be provided without the built-in cutting saw ring blade, which is therefore provided as an add-on accessory which snaps into place within channel located along the top and channels on opposite sides of the downwardly extending round wall of the body of the self-seating electrical device. The self-seating electrical device also has two or more fasteners, such as three toggle swing clamps, to secure the electrical device in place in a cutout in a ceiling or interior or exterior wall panel, where the cutout is cut by the forward saw teethed blade edge of the electrical device.