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Tech In Plain Sight: Incandescent Bulbs
(hackaday.com)
This is a most excellent place for technology news and articles.
I'm betting on bad airflow on some fixtures, installed by a landlord.
And/or bad switches? Legrand branded.
Some bulbs have cracked plastic housing.
They are rated 220-240 V AC, 50/60 Hz, I think have constant current regulator.