Abstract: A modular interchangeable electrical work box having a housing for mounting one or a plurality of electrical devices, such as switches or outlets. Each support module is adapted for supporting a specific electrical component and the support modules have fastener insert sheaths for fasteners, such as screws or nails, for attaching the work box to a residential wall stud so as to permit interchangeable positioning within the housing. The box is interchangeable in that it can be used for either a new work box in new construction or for an old work box for replacement of existing work boxes or upgrading electrical service.