A receptacle assembly with improved EMI leakage reduction and construction is described. The assembly includes a housing in the form of a guide frame that has a hollow interior which accommodates the insertion of an electronic module therein. A heat sink is provided to dissipate heat generated during operation of a module and the heat sink has a base portion that defines a ceiling of the hollow interior. An opening in the top of the guide frame provides an attachment location for the heat sink. A separately formed base plate is inserted into the housing and it defines a bottom of the interior of the housing.