The one in Dead Money is in Salida Del Sol North. From the fallout wiki:
"From the southern-most entrance to Salida del Sol South (inside a house in Salida del Sol North), proceed down the stairway and out to the street then look behind you for the entrance hole in the wall above. This area can be reached by going up the
stairs located around the corner to the southeast and following the rooftops back towards the hole."
It's in a room above the stairs (look for hole in wall) that has a lot of desks which are stood on end against the back wall, the snowglobe is on a shelf, also look in the wall vent in the same room, ( on the right, high up) for some loot as well.