I have several different circuits, connected to the same panel on different breakers, that are flickering while turned on. Some of these are fluorescent bulbs and others are LED. They will come on and then every five minutes or so they will flicker on and off maybe 10 times, then go back on to steady state.
Since this is happening on different breakers, I assume it is not related to the wiring or breaker of each individual circuit. I haven't noticed that when it happens to one circuit it happens to the other, so timing is somewhat different across circuits.
What are some possible causes for this behavior? How do we test for those things? Electrician is so far stumped.