System comprising an electrical installation box and a support member attached to said electrical installation box for flush mounting on a wallboard, said support member comprising: - a rear surface removably attached with the electrical installation box; - a front surface to be fixedly attached with the wallboard; and - a central cavity of matching profile with entry portion of the electrical installation box, said front surface and rear surface are extended outwardly about said central cavity, wherein said rear surface comprises: - at least a set of fixing members (102-1,102-2) disposed about said central cavity and extending from said rear surface to removably attach with the electrical installation box; - at least a set of guiding members disposed about said central cavity for aligning said fixing members (102-1,102-2) with said electrical installation box; and - at least a receiving provision which receives a split nut assembly, and wherein said front surface comprises: - at least a set of releasing slots (108-1, 108-2) disposed opposite to every fixing member (102-1,102-2) on said rear surface such that said releasing slots (108-1, 108-2) extend up to said rear surface to release said fixing members (102-1,102-2) from the electrical installation box; - the split nut assembly which has clipping members; and - at least a fastener aligning slot to guide fasteners into said split nut assembly, said at least a fastener aligning slot is disposed opposite to said at least a receiving provisions for receiving the split nut assembly of said rear surface. - a rear surface removably attached with the electrical installation box; - a front surface to be fixedly attached with the wallboard; and - a central cavity of matching profile with entry portion of the electrical installation box, said front surface and rear surface are extended outwardly about said central cavity, - at least a set of fixing members (102-1,102-2) disposed about said central cavity and extending from said rear surface to removably attach with the electrical installation box; - at least a set of guiding members disposed about said central cavity for aligning said fixing members (102-1,102-2) with said electrical installation box; and - at least a receiving provision which receives a split nut assembly, and wherein said front surface comprises: - at least a set of releasing slots (108-1, 108-2) disposed opposite to every fixing member (102-1,102-2) on said rear surface such that said releasing slots (108-1, 108-2) extend up to said rear surface to release said fixing members (102-1,102-2) from the electrical installation box; - the split nut assembly which has clipping members; and - at least a fastener aligning slot to guide fasteners into said split nut assembly, said at least a fastener aligning slot is disposed opposite to said at least a receiving provisions for receiving the split nut assembly of said rear surface. - at least a set of releasing slots (108-1, 108-2) disposed opposite to every fixing member (102-1,102-2) on said rear surface such that said releasing slots (108-1, 108-2) extend up to said rear surface to release said fixing members (102-1,102-2) from the electrical installation box; - the split nut assembly which has clipping members; and - at least a fastener aligning slot to guide fasteners into said split nut assembly, said at least a fastener aligning slot is disposed opposite to said at least a receiving provisions for receiving the split nut assembly of said rear surface.