Will my homeowners insurance replace my electrical box?

Quick answer is NO as that would be a maintenance issue to upgrade your home. If your electric line maybe "arced" and caused a TV or other appliances to "fry" then those would be covered by the arcing. But to have the panel replaced because it is old or needs an upgrade - NO.

Consumer's of insurance should know that insurance is for things that are sudden & accidental and not for maintenance type issues. As the owner of a home, you are responsible to upkeep or take care of issues like this. As a fellow homeowner, I know this can be expensive to upgrade but that is the cost of homeownership.