97 Lumina flickring lights

I have 97 Lumina with 3.1 engine. My lights keep flickering and the dome light does not work when doors open. The dome light works with dimmer switch. I had the Battery and Alternator tested, they are working fine. I have checked all the cables, they seem to be tight. I read while back someone mentioned about a relay or fuse on the driver side that could make the lights flicker? Does anybody know where the dome light switches are in the doors or how the dome light works.

Any help is greatly appreciated.