How common is it to get an MBB interview invite to an office you didn't recruit for?

As the title says I got an invite to an office I didn't recruit for at all. I'm not complaining because any interview is better than no interview but I'm starting to think this is some kind of mistake on the recruiters part. I've heard some friends say "I've never heard of this happening, it's probably a mistake" and others say not to worry about it.

I did mention on my app I was open to working anywhere which is true, but what are the chances an office would invite someone to interview when they have no connection to that location? 2nd year MBA student recruiting for full time BTW. 

Thanks for any help