Related to this question, link, I have a very similar-looking dimmer and light. The dimmer is very old, at least 20 years, and the light is perhaps 5-8 years old. It never used to flicker. This week it began, about a single flicker in a minute (but not regular).
I'm curious what might have caused it to flicker just now, and whether it makes more sense to look for the trouble in the dimmer or the light itself.