The disclosed concept pertains generally to secondary terminal blocks and, more particularly, to apparatus and methods for isolating the secondary terminal blocks and associated wiring in electrical switching assembly enclosures. The apparatus includes a housing having an outer surface structured to form a cavity therein. The apparatus is positioned in an enclosure which includes an electrical switching apparatus and one or more secondary terminal blocks. The one or more secondary terminal blocks are positioned in the cavity such that the apparatus at least substantially isolates the one or more secondary terminal blocks from the electrical switching apparatus. Further, the apparatus is effective to substantially isolate the secondary terminal blocks from temperature and pressure effects resulting from an arcing fault occurring in the enclosure.