From what I’ve read on other posts, this is pretty common. We moved into this home less than 1 yr ago and we’ve been noticing these lines more and more in the ceiling especially this summer. Is there a way we can fix this so it doesn’t happen anymore? The house was built around 1960 and when we moved in the home was remodeled. This has been the only thing that has been causing concern for me and I was curious if there was a way to fix it.
That appears to be where the joint was drywall taped and filled with drywall joint compound. Moisture or movement could cause this to happen. Is the home air conditioned. To repair it you need to clean out the original joint, tape it and fill with drywall joint compound and sand it smooth. This is a very messy process. I went through that many years ago, there may be better methods today, but if so I am not familiar with them. This link to SFGate will take you through it step by step.
That issue is cosmetic not structural.
It was either a bad tape job or moisture/humidity are affecting the joints in your ceiling's drywall.
The main reason it's so noticeable is because of the adjacent ceiling lights. If the light source was a floor lamp or mirror vanity lights then it would be less noticeable.
Unless you can guarantee perfect humidity conditions then fixing it will be costly (if subcontracted), lengthy (if DIY), messy, and ultimately futile because those lines will return.