An electrical switch apparatus comprising at least one set of contacts including a movable contact and a stationary contact, at least one chamber surrounding the contacts, a first support for supporting the chamber, a second support for supporting the stationary contact with respect to the chamber, an adhesive for attaching the first and second supports to the chamber, a non-circular drive shaft, a connection mechanism for coupling the moving contact to the drive shaft, a locating mechanism for securing the connection mechanism along the drive shaft, a coupling mechanism associated with the drive shaft for transmitting rotational energy to the drive shaft, the coupling mechanism having an adaptor that mates with the drive shaft with a clearance between the adaptor and the shaft, and a castable material filling the clearance to form an interface between the drive shaft and the adaptor.