Hacked I think

Jul 11, 2018
My wife phone and my phone show that they are messaging each other but we are not messaging each other. Every now and then my wife says that she sees a message pop u on her screen and then disappears. We have cancelled Facebook and all security doesn’t show any faults and our phones are not linked. What can I do to stop this?
antivirus can´t find anything unnormal?

Maybe it´s advertisment

If not and it´s infected, I would factory reset the phones and start from the bottom. Backup your phones before doing so. Scan the files you backuped with a PC antivirus software like "malwarebytes"