A gas discharge lamp having a translucent envelope enclosing a light emitting assembly that includes a baffle and an anode separated by one or more spacers made of an electrically insulating material such as ceramic, which are oriented towards a heated cathode to receive electrons emitted therefrom. Each spacer has a front surface, a rear surface, a top surface and a bottom surface including a transverse cavity formed between the front and rear surfaces to permit electrons to flow through. The cavity extends from a first through-hole in the front surface to a second through-hole in the rear surface of the spacer. Further, the cavity includes a gap for allowing conductive materials that may sputter or evaporate from the anode or the baffle to escape from the cavity to prevent short circuiting between the anode and the baffle.