Called, didn't leave a message.

The number called looked familiar I answered, there was no contact, I did try to call the number back and it is an "out of service" number.
Although I cannot provide too much info I can write for sure that it is most likely a type of scam due to the out of service recording

rand 3 times and then they hung up.  did not recognize the phone number so I did not pick up.  The caller ID said "Test Code"

it was from someone asking if you receive food stamps or medicaid you could be entitled to free cell phone didn't answer message left on machine

At least I know what it is now. that's what they call the "Obama" phones.  It a free cell phone that you get free minutes. I already got one, so not answering when that # comes up