Phone calls from strange number?

Question

I'm in California, and don't know anyone from Oklahoma, but I received a call from there. I did not answer, but when I tried calling back, the number was invalid. Any thoughts?

Answer 1

Could be a wrong number, charity organizations are exempt from the do-not-call list so that could be it, or a collections agency...

Answer 2

I'm based in UK (you've submitted this on UK & Ireland yahoo answers)

but I usually google unknown numbers and you find they are someone trying to sell you something, or someone else has already found out who is trying to contact you.

I would never call them back as in Uk we have many expensive scams.

Good luck