While corrosion in electric sockets, know as fretting corrosion, can occur in AC connections, it is most prevalent in DC applications. By definition, fretting corrosion is caused by the friction of loose contact points that produce a continual arcing (spark) effect, causing a build-up of electrons between the surfaces. Minor corrosion can be removed from electrical sockets by abrading the contact points with a specially designed wire brush, screwdriver or sandpaper. Electrical sockets that have become severely corroded will need to be replaced.
Disconnect the power to the socket.
Spray the corroded contacts with the electrical contact cleaner.
Rub the contact points with the wire brush. If the brush fails to remove all the corrosion, wrap the tip of a screwdriver with a small piece of sandpaper to scrape the contact.
Apply a small amount of electrical contact lubricant to the contact points to inhibit further corrosion.