I have personally seen incandescent and CFL bulbs above diffuser panels in suspended ceiling setups (even more bizarre than a fluorescent shoplight mounted above diffusers mimicking a fluorescent troffer), mercury vapor recessed can lights inside a home, and a restaurant using real antique 100 year old radial wave streetlights (now repurposed as overhead table lighting).

Let's hear your intakes!

In a cold region, a fluorescent fixture with a heater wire wrapped around the tube, to warm it up doing the startup. But it was done in a crude manner, where it was all manual, even the tube was started with a switch instead of a normal starter.


I also saw an HPS lamp used indoors without any protection. The 250w bare bulb was hanging at head height without any cover.