Random ad's playing in background - PLEASE HELP

Random ad's have been playing in the background on my phone at all different times of the day. It will continue to play when I lock the phone or even when I have closed every app running in the background and closed all tabs in Safari. It's the same Honda add and has been happening off and on for months now. Does anyone know how to fix this or what it is? I have to keep my volume all the way down because it will randomly play at top volume a Honda add at my desk when my phone is just sitting there.

PS: Sometimes it will do it 5 or 6 times a day and then the next day it might not do it at all.