In the city where I live, we have 3 different MP's that opened up a legit shop in a house. Some do that here, because leasing commercial space is too
expensive. But at the same time, only 2 of them have a small sign in the window, so if you blink, you miss it, haha. They rely more on ads, than walkins
from the street. Could that be the case with that one ?
Post Edit : Just looked at the google street view of that intersection (227 and dewdney), lots of little strip mall places around there, who knows.
There is a phone number in that ad to call and ask, obviously would be the ultimate thing to do.