I got this too, ID says it's a wireless caller. Was surprised to hear a robotic voice saying that the IRS is filing suit against me. I suspect it's a Scam to get you to answer or call back.
Received call at 10:16 am and again at 2:57 pm. Same Robo Call that IRS is filing a suit against me. I put it on reject list. I reported to the Donotcall.gov as well. SCAM don't fall for it.