1997 Buick Lesabre Exterior Lights

When I turn my car off the lights will not go off. The entire exterior lights are on including the headlights, tail lights and parking lights. The twilight switch is as low as it will go and they will not shut off when it is pushed all the way to the left (which is supposed to shut them off, when the car is in park). If I wait 15 minutes they will finally go off. Usually I disconnect the battery, because it kills it.