A more primitive dry cabinet can be made of a box with a lighbulb in the base. The lightbulb warms the box, thus reducing the relative humidity to a level congenial to whatever is stored inside. Think of the old welder's trick of storing their stock of rods on a junked refrigerator with a lightbulb inside.
Now there's something I haven't thought about for years. When in SE Asia for uncle sugars follies we had wardrobes(being generous there) with a small bulb in it to prevent mold & mildew. In more than two year no one in the platoon had any problems with it.
In a smallish cabinet even a 71/2 Watt lamp would do.