Green bubble with smiley face notification not going away for SMS msg.

[AC Question]

Last night a green bubble with a smiley face in it popped up in my notifications. This is the same emoji that comes if you have an SMS txt msg. The thing is, my tablet only has messenger for Facebook. It's not connected to a wireless provider so I'm not receiving or even have the SMS app in my tablet. When I try to click on it, nothing happens, when I look in my widgets, nothing, if I try to swipe down on the notifications, it doesn't show up in them. I know I can't have a text message so what is up with that? I'd just like to know If there is a way I can find where it originated, view it or get rid of the notification. I have a Samsung Galaxy Tab 4. The white model. Thank you!!