Definitely wait until you get the clarification. Note the number 2 there.
He could be writing it as you are thinking, with 150 being the house number. That would make the address:
Victor Rojas
150 Calle 1 (like, 150 1st street)
Blah Blah City, State, Zip
Alternately, the 150 may be the apartment number. Note the number 2. It comes before the street name, which would be fairly standard for both PR and the States really. In that case it would be written as:
Victor Rojas
2 Calle 1 Casa 150 (2 1st Street, APT 150)
Blah Blah City, State, Zip
The way he wrote it is definitely ass looking though, especially with no spaces or line breaks.