Okay, not really foreign as in from a different country or world per say. That works too but I'm talking about the use of a character in a story who is new to the one location and they don't know the ways so it's okay for someone to tell them what is going on. It's a device sometimes used to tell without telling because it's dialogue but it would sound weird of two people from the same place rambled to each other explaining things that they should already know. The new guy is a good option, that or a little child who asks lots of questions.
In YA and Middle Grade, the new kid to school is common. I've read submissions with them, unpublished stories and published books all with new characters either as a main or secondary one. This can be a new character to the city, the country, the world or even the universe. Also, when it involves a new world or systems that need explaining, that can be used to the writer's advantage.
On the other side of the coin, it can also be for someone who is not "new" to the place but is so different than the others that they seem foreign. Their differences can be anything but it makes them stand out and if they are the main character sometimes is part of what becomes the conflict.
I have to admit, I have a few YA books that I'm writing right now that have the foreign character. In fact, all three that I have going have that to some degree. Two of them are the new kid (one a pov character and the other a secondary character) and the other one is both the non-new pov character with a new non-pov one.
Tattle Tell - In this one the main character isn't new but the boy who befriends him part way through the story is new to the town.
Lighting the Wall - New boy to the village is one of the pov characters out of two. The other one is from the village and can help the new one figure out how things work.
Ottohahn in E Minor - Ottohahn isn't new to his city but he doesn't fit in well. He tries and is intelligent but he's also artistic along with a skilled musician which no one there understands because they see it as something for leisure only. There is a new boy that he meets who sneaks into the village.
An adult story example - In the urban fantasy one located in Salt Lake City, the main character definitely feels foreign to the location. She gets the help of someone from the location to get used to it, but at first she is pissed when she finds out that SLC is her destination and not just a lay over.
Any new kids/people in your stories?
How about those that seem or feel foreign?