If you get a call from a number you don't recognize, don't answer. Your phone should have a feature that allows you to block all calls from those numbers. "Private number" just means that they've blocked caller ID, which can be done easily by dialing *67 before you enter the number (you can do it, too). It's probably a telemarketer.

I get a fax, number not in service or sometimes a person….dialed wrong number.

Spoofers are getting slick. I’ve been getting calls that show Medicare. Dial that number and get a fax. I called Medicare and was told they do not call people.
A couple of times, lately I get calls that the ID say it’s my doctors office. I know there are no workers there with a Hindi accent. I’ve calledo the office at the the number on the ID and it is their office. Now if I get a call from that number with an accent, I tell them I’ll call them right back and Hank up. I don’t. Have not got another one after that. If it’s a number that might call you, use that.
I also bought a canned air horn for boated, $8.00, that works great and the don’t call back.
Good luck.

you stated (yesterday, if I recall) that you locked your credit down.

If that's true, you really don't have that much to worry about. Your data may be out there, but they can't open any lines of credit/loans using your info.

As stated above, just block numbers that aren't in your contact list...if it is something important (doctors office calling from an extension for example) they will leave a message.

If someone calls from a bank, credit card etc...ALWAYS ALWAYS ALWAYS tell them you will return the call and then call the number on the back of the card, etc.

NEVER NEVER NEVER "move money" from one account to another because someone on the phone tells you to.

NEVER NEVER NEVER listen to/believe someone on the phone (IRS, sheriffs office, Medicare, etc) saying you will be arrested etc if you don't send them money "right now!!!" THAT NEVER HAPPENS!

Follow these steps and you won't get scammed.

Plus, all of the numbers in my phone, including doctors and such, have their own ringtones. If a number that is not on the list calls, I hear this:

and I don't answer. I have never had anyone call me with something worthwhile that did not leave a message.

It sounds like a scammer/telemarketer.

I don't answer.

Unless I'm in a foul mood and feel like fucking with them.

I probably get 20 to 30 calls like this per day, combined, on both the landline and cell phone.