how is this happening?

[Timmy]

for some reason it seems like recently im getting added by fake ppl like ppl with one picture or people with no mutual firneds or ppl that just are simply fake as fuck ppl that made a facebook 15 hours ago and shit like that.. but my question is how are they finding me out of everybody on facebook???

[pri✍]

If they are fake people, they don't find you specifically, more like pickpocket, they just see you & pick your pocket. Then they'll find out from your About that you open for your Friends, your photos, status, your friends list to find bigger fish or more interesting to hack, etc. You've warned not to add people you don't know.

[Kittysue]

They contact everyone. Unless you have a private profile they will contact you
If you've ever "liked" a page they can find you there.
Set your profile to private so only Friends or Friends of Friends are able to contact you and see your profile