This receptacle was found on a home inspection in Selden NY yesterday, and the damage is evident. This receptacle needs replacement, and the old snap tight cover is in need of updating to the modern 'in-use' cover that offers more protection than this one in the picture. As the homeowner, you should also be testing these by pushing in the 'test' button to trip it. You will never know if these are working properly unless you test it.  If it makes a funny noise, or does not reset immediately its a sign it needs to be replaced.