Silly quest ???
First thing to do is check to ensure the tire pressure is accurate for the weight. If too much it will make the coach ride and drive like a log wagon! Making things shake that may normally not!
Once the tire pressure is good, you can now start finding the things that are rattling. Easier to have someone drive while someone walks around and identifies what is moving around.
Dishes, pots, pans, glasses, etc. are all suspects.
In our case, the three burner cooktop was not bolted in correctly so a screw there stopped our biggest source of noise.
You will find things that still rattle, a well placed paper towel or dish cloth works wonders on microwave turn tables and racks.
Terry & Kim
2015 Berkshire 38RB
2007 Jeep Wrangler JKU