Worn key

 is a miscellaneous item in Fallout: New Vegas.

Characteristics
 unlocks the door to the basement in the Nipton Town Hall This door is adjacent to the stairwell leading up to the second floor. It is located on the left side, not far in from the entrance to the Nipton Town Hall.

Location
 is sitting on top of several papers on the counter behind the reception desk that is on the right side, just as you walk inside the Nipton Town Hall.
 * Be careful of the Frag mine (Fallout: New Vegas) that is on the floor next to the counter.
 * Also be careful of the Legion mongrels that roam the hall in the lobby