A photo of an electric bug zapper which appears to be of a very old design. This zapper appears to consist of an assembly incorporating a light bulb surrounded by windings of fine wire with a second, much smaller light bulb near to the larger bulb. The zapper assembly has an Edison screw base extending from one end so that the assembly can draw power from an existing light bulb socket. This Collectors Weekly page shows a zapper that is similar (possibly the same model) and which has a paper cylinder fitted between the bulbs and the wire windings.