The answer to 'why is my fuse box burning smell' is that a burning smell from your fuse box is a serious issue that indicates an electrical problem. This could be caused by a faulty circuit breaker, overloaded circuits, loose connections, or other electrical issues. The burning smell is a sign of an electrical fire hazard that requires immediate attention.
You should not attempt to investigate or repair the issue yourself, as electrical work can be extremely dangerous. Immediately shut off power to the fuse box and call a licensed electrician to diagnose and fix the problem. They can safely inspect the fuse box, identify the cause of the burning smell, and make any necessary repairs or replacements to restore safe electrical service to your home.