An acoustic warning device for a vehicle is disclosed. The fixture comprises a body forming a light-emitting opening, lighting components including at least one lamp in the body, a lens covering the opening, and a conductive grid across the opening, the grid being separate from the lens, electrically connected to the body, and positioned between the lighting components and the opening. A parasitic leakage barrier is disposed above the first buffer layer. A magnetic scrubber includes a power unit and a pad unit. In one embodiment, the catalytic layer may be deposited in the feature to act as a barrier layer to a subsequently deposited conductive material.