Abstract: The unwanted introduction of contaminant material into the interior of a craftsperson's telephone test set is effectively prevented by modifying the housing configuration of the hand and face-conformal segment of the test set to incorporate a resealable module that is sized to accommodate printed circuit components that are to be protected from contaminants in a compact nested arrangement. The resealable module comprises a shell configured to be insertable within a receiver-retaining portion of the test set body. The shell has an acoustic opening which is adjacent to an acoustic energy coupling portion of the test set body, when the module is inserted into the receiver-retaining portion of the test set body. The acoustic opening is configured to seal a bottom portion of the shell with the test set body. A printed circuit motherboard has a plurality of printed circuit modules and is supported on the shell, so as to provide an acoustic chamber within the interior of the shell adjacent to the acoustic opening.