Someone is spoofing the caller ID system.
It happens all the time.
http://www.fcc.gov/guides/caller-id-and-spoofing
why do people answer the phone when unknown is calling them, not me
The only reason I do is because I've seen other people do it. I just figure that's what people are supposed to do. If you're scared of your phone, something's wrong.
Honestly, I don't always answer it though. Other people will absolutely always answer their phone every time it rings no matter what. I don't understand that either. Your phone is there for your use, it's not something that you are obligated to answer for anyone elses purposes. If not then why would someone saddle themselves with such a burden as a phone?
If I don't recognize the number, I don't answer. If it's important, they can leave a message. Curiously(or not) I get few messages :^D
I get spoofed calls all the time. I just don't answer unless I recognize the number. If it's important, someone will leave a message. I sometimes wonder why I even have a home phone. A good 95% of the calls we get on it are telemarketers, and that's being conservative.