1995 Chevrolet 1500 Pickup Q&A

1995 Chevrolet 1500 Pickup Question: Why on cold nights ,would the horn start blowing and the interior light come on?

Only when temps are below 25. -
Answer 1
have shop check -
Answer 2
ANY aftermarket/dealer add-ons , such as keyless entry or aftermarket radio , security system? Had any kind of collision/body work done? -