Received 2 calls from these people. When you call back their number (blocking your own of course) you get a pre recorded message of gobbledygook. So.....
Blocked and reported

Air Duct Cleaners with thick Indian accent. I said someone is at my door and requested a number to call them back. It was a fake number.

Called and didn't leave a message. Name on CID says Zehava Toladano. When I googled it I found other numbers associated with that name here on 800 Notes - says they are some kind of cleaning service.

Didn't answer never will, blocked.

I just received a call and voice mail from a number 415-236-3632 which this lady claims to be an officer and representing the IRS and to call back.  this is a complete scam so if anyone gets a call do not answer.  they don't say who they are calling and looking for.  for one thing the IRS does not call, they send out letters and they know who they are looking for.  and it is a recording and they just read off a piece of paper what to say.  Like robots.
don't answer.