PRIVATE Q: I have call-blocking on my home phone to stop robocalls and scam calls from getting through. It works pretty well. It’s called Nomorobo.

But recently I’ve received calls every day from the number 608-371-6666. The person leaves the same voicemail every day, saying she’s calling from a debt collection agency and I’m supposed to call back a toll-free number, not the 608 number. I looked up the toll-free number; it belongs to a company called ConServe, which collects debts for back taxes, student loans and other things.

I’m retired and have no tax liability. I’ve never owed back taxes. I’ve never had or co-signed for student loans. So these calls must be a scam. Why are these people calling me and how to do I get it to stop? What should I do? Can I block the number?

D.R., Mayfield

A: You’re smart not to answer calls you’re not expecting and from numbers you don’t recognize.

You’re also smart to have signed up for Nomorobo to block most of your unwanted calls. Nomorobo is offered by most phone carriers and it’s free for landlines.

There’s no way to know whether the calls you’re getting are coming from a con-artist or from ConServe. I don’t suggest that you answer one to find out. If it’s actually ConServe, it could have a wrong number in its database or it could be hunting for someone who once used your phone number.

Nomorobo is set up with a fail-safe to allow a call from a real person to actually be able to get through if Nomorobo has incorrectly identified as a scam call, Nomorobo founder Aaron Foss said in an interview.

“It would be pretty dangerous to not let humans through if Nomorobo accidentally misidentifies a phone number,” Foss said. “So, we make the person prove they’re not a robocaller and then send the call back to them with our caller ID.”

If a call is blocked because Nomorobo believes it’s a robocall, the caller will hear: “This phone is protected by Nomorobo. In order to prove you’re not a robocaller, please enter the number …” The caller is asked to enter the randomly provided number. It could be 16. It could be 42. Whatever. If the number is provided correctly, the call will go through. But it will show up on the receiver’s end as coming from 608-371-6666, no matter where they’re calling from. For more information on this, go to http://www.6083716666.com/

“That being said, it’s very safe to block our number in cases like you describe,” Foss said. “Our misidentification rate is less than a tenth of a percent.”

If this debt-collection call was legitimately intended for you and was for something big like back taxes or an unpaid student loan, it’s highly unlikely your first notification would be by phone. You almost certainly would have gotten notices by mail for tax issues, said IRS spokesman Luis Garcia. Ditto for state and local tax issues.

If you had answered the phone for a call like this, my advice is not to confirm a name, provide a name or provide any other information. You said the caller didn’t use your name. There’s nothing good that can come from providing or confirming information. If you had answered and the caller said she was calling about collecting a debt, I’d advise you to tell the caller to send you notice in writing as required by law. Again, don’t give your name. And if the caller doesn’t have your address (where you lived for decades,) then that tells you all you need to know.

Consumers can also use the 608-371-6666 number to report nuisance calls to Nomorobo.

Q: Thank you for your column about people’s actual dates of birth appearing on their license plates. The practice is most certainly bad security hygiene and the BMV’s decision to print them is irresponsible.