Whistling and door locks keep re-locking

I was driving my reliable 1997 Carolla when I heard a high pitched whistling sound,it was not very loud. Suddenly my horn started blaring so I pulled over and turned off call. The horn continued. I noticed the antitheft light was on so I used the fob to turn it off. The horn stopped but not the whistle. A man banged around under the hood, including the fuse box, and the whistle stopped. I drove for another 15 minutes, left the car for about 20 minutes and when I came back the car was whistling again. Shortly after, the locks kept re-locking themselves continuously. AAA man removed the anti-theft relay (I think) and cut some wires supposedly to power locks. Nothing changed. The car is under 2 feet of snow right now and neighbors are knocking on my door to tell me that the car is making noises like something is on. By the way, the 2 left doors were replaced after an accident about 18 months ago. the rear lock never worked with the fob. Where do I go from here? mechanic, body shop that replaced doors, or dealer?