I thought I posted this before but I don't see it in search results. I'm finding that if I use a vacuum cleaner or a corded drill, lights on separate circuits dim. I would expect this for lights on the same circuit but I don't know if this is normal for lights on different circuits to do this. I've also noticed that sometimes a less noticeable dimming can happen when the neighbors central air unit turns on. I'm running off of a 100amp service so I know I'm at the lower end of what's normal nowadays but I know for a fact I never have anywhere near that kind of load with only myself in the house.
Is this something wrong with my house or service and what can I do about it, if anything?