My phone just started doing this. I get a text with my husbands cell number on it when I call him. A setting somewhere? He does not have texting enabled on his phone.
Welcome to Android Central! Is he actually answering the phone when you call, or does this only happen when he doesn't answer? It might be due to a Quick Response. If he's rejecting the call and swipes up instead of swiping to the left, that triggers a Quick Response to be texted to the caller (like "Can't talk right now, sorry"). If his Quick Response was edited to be blank, then you might just get a blank text from his phone number. See this article for more info: http://teckfront.com/answer-call-sms-quick-response-android-kitkat-phone/