How to cover under the cabinet fluorescent light fixture?

fluorescent light fixture has a ballast transformer built in and that needs air to cool. if you want to hid you would replace it with led lights or puck lights.

Thank you, I'm kind of looking for something to hang in front of it so guests can't see the bulb, so I think it would still be able to get air

Add a,2" rail to the already rail in front. Can stain or paint it to match or an accent color. Can use small braces screwed from behind to attach.

Look at the newer LED fixtures and other under cabinet fixtures. They are extremely inexpensive, use less electricity, don't get hot, etc. It may make a lot more sense to just replace them.

I put lighting pucks under my oak cabinets about 10 years ago. I don't remember a lot of the details, so I have attached pictures. I sourced 3 inch wood "molding". I think it was oak, and I don't remember exactly what the name of the molding was. (Chair rail, window molding, etc). I took a drawer front from the cabinets to a paint store to have them match the stain. I then stained, cut, and attached the molding to the cabinets with 3/4 inch wood pieces. I hope this helps, and gives you some ideas. Good luck.