Remember the old, aggressively-yellow street lighting that pre-dated LEDs, ceramic metal halide, and high pressure sodium? Turns out it’s very useful for physics, as the two strong emission lines near 589nm are handy for various experiments.
The lamps themselves are fairly tough, and the ballasts that operate them even more so. But, eventually, they burn out.
General Electric ceased production on these lamps back in 1972. So, no, sorry, replacements are not readily available.