I would choose "wall outlet" over "wall socket".  One problem with "socket" is that it's commonly used with lightbulbs, but lightbulbs are not associated with outlets.  It's a matter of clarity.

The choice reminds me of one you have in Portuguese:  aula and classe.  You are teaching English.  What are you teaching?  You are teaching an aula, right?  Where are you teaching it?  Although you could say you are teaching it in a classe, chances are you would choose a second term:  sala de aula.  Why?  Clarity.  It's not a matter of what you can say, it's a question what you actually say.