Typical party-wall construction for townhouses, where the party-wall is on the property line, is two layers of 1" type X drywall panels, each 24" wide and 8' high, with metal tracks to hold it together. This provides a 2-hour fire rating.
The metal tracks are attached to the framing of the adjacent interior wall with metal clips that will melt in the event of a fire, allowing the adjacent structure to burn completely down without pulling down the party wall.
With this type of construction, an outlet installed in a party wall isn't actually in the party wall. It's between the interior drywall and the party wall.
For an apartment, I would think that what you'd have would be a regular firewall, not a party wall.
