Yes, don't eat wax! Wax is not food. Yes, all right, your mother and many other well-intentioned people may have melted paraffin into chocolate to make it easier to coat things like frozen bananas. Some recipes even call for it. But that doesn't make it right.
And, yes, the US Food and Drug Administration has approved "food-grade" paraffin, even though it is a derivative of the production of crude oil. Mostly it is used to coat fruits and cheeses. While food-grade paraffin is technically edible, it is not digestible; it passes through the body without being absorbed. Beyond that, after hours of searching, we have not been able to turn up any sources of food-grade paraffin. Do not assume the paraffin for sale (for canning purposes) in your supermarket is food-grade; it is not.
There are better ways to thin melted chocolate so that you can dip your bananas. The fanciest is to go to a chocolate shop and purchase couverture - a very high quality chocolate containing at least 32% cocoa butter. Candymakers use it for dipping fine chocolates and fillings because it forms a thin, glossy shell. This would produce gourmet chocolate-covered bananas, and will have your friend's relatives singing your praises for years to come.
You can also purchase something called chocolate confectionary coating, which is technically not chocolate since it contains no cocoa butter, but which is melted and used for dipping such things as ice cream cones and other lesser-quality chocolates.
The final choice is to stir some solid vegetable shortening into your chocolate in place of the evil paraffin. We'd try a quarter of a cup per pound of chocolate. If the chocolate still seems too stiff, add more shortening a tablespoon at a time, until you think the consistency is right.