What do you do about a vacuum leak in an automatic Ford Tempo?

first find the leak. Take a can of carb cleaner or something similar and spray around all the vaccum hoses, connections, intake gasket, etc and listen for the rpms to raise in response to you spraying. If you notice anything. investigate further for a bad connector, hose, gasket, etc.
If you don't want to do that you could also take it to a shop with a machine made to find the leak that pushes smoke through the system and you can easily see the leaks then.