First, turn off the power and remove all the bottles, shelves, and drawers. Mix two tablespoons of baking soda with a quart of warm water. Use a soft cloth or sponge with that solution to clean the inside, then rinse with water and wipe clean.
Let it dry naturally with the door open before you turn it back on. Don't use soap, detergent, scrub powder, or spray cleaners inside. For the shelves and bottle frames, use a soft cloth with soapy water, then dry them.