A compressible sealing gasket for supporting a cable in a wall opening contained in a housing wall includes a pair of gasket sections each having a planar surface that contains a recess, and at least one integral compressible sealing projection extending from the planar surface adjacent the recess. When the gasket sections are placed in an assembled condition with their planar surfaces in contiguous engagement, the recesses cooperate to define a cable opening for receiving a cable, and the projection is compressed between the gasket sections to seal the space between the gasket sections adjacent the cable opening. Preferably two laterally spaced integral sealing ribs are provided in each recess, which sealing ribs extend transversely completely across the recess and terminate at each end in a sealing projection that extends upwardly from the associated planar surface.