Home Wiring Circuit Diagram - Links to other sites I consider worthwhile: NOTE - some links are moving to the separate "Mad Scientist Central" page. Sam Goldwasser's site at repairfaq.org! The laser, strobe, and fluorescent lamp documents that are mainly of his authorship can be found there as well as here.. Note: The 3157 led bulb will function in either 3157 or 3156 sockets. In the 3156 socket, the 3157 will have extra contacts that are not connected to anything. The 3156 bulb will not function in the dual bright dim mode in the 3157 socket..