Windshield Wiper/washer Linkages problems of the 2003 Mitsubishi Galant

I have a 2003 Mitsubishi Galant ES. It has 69000 miles. As of right now the problem with my car hasn't caused an accident but I am afraid in the future it might. It started with the radio staying on even after the key is pulled, then it went to that if I used the wipers and the headlights at the same time, the wipers wouldn't shut off until I shut the headlights off. We then had to pull the fuse for the horn, because while sitting in the garage, not running, hadn't been running for several hours, the horn started blaring, and wouldn't go off until my husband disconnected the battery. I am scared for my own safety as well as others, to use the cruise. I am scared it will stay on, and I would be involved in a severe crash. Please help, no one seems to know exactly what the problem is.