A method of attaching a housing (such as a security system device housing) to a wall. A housing is provided with at least one mounting portion that has a mounting hole surrounded by a substantially thin lip. The housing is held by the installer in the exact desired position on the wall. The installer the inserts a wall anchor through the mounting portion and into the wall, typically with a screwdriver. The wall anchor has a cylindrical body with a flanged end and an insertion end, with the body having an exterior thread disposed thereon and the insertion end having a generally flat pointed extension of the body. The flanged end of the anchor has a recess suitable for insertion of the screwdriver. The installer inserts the anchor by pushing the extension through the mounting hole of the mounting portion and into the wall with the screwdriver engaged in the recess such that the extension is substantially within the wall. The installer then turns the wall anchor with the screwdriver tip inserted within the recess such that the exterior thread engages the drywall and draws the wall anchor into the wall until the flanged end overlaps the lip of the mounting portion and presses the lip against the surface of the wall. By making the lip tapered to mate with the taper of the flanged end of the anchor, the head of the anchor may be flush with the surface of the housing, although this is not required.