Line an 8 by 8 inch baking dish with aluminum foil.
In a large bowl melt the chocolate chips in the microwave according to package instructions.
Stir in the sweetened condensed milk, the vanilla extract, and the whiskey.
Pour the mixture into the baking dish. Cover with aluminum foil and let set completely (about four to eight hours). Refrigerate for 1 hour before slicing. This last step of refrigeration is optional, but makes the fudge slice nicely.
Enjoy and store in an airtight container for two weeks.
Notes
Make sure you measure this out. A can from the grocery store is 14 oz and more than you need. Also make sure you are buying sweetened condensed milk and not evaporated milk as they are on the shelf next to each other and that is an easy mistake to make.