when somebody is either so intoxicated or just a terrible driver that they are driving in the middle of the road on the dotted while line, as if they were Mrs./ Mr. Pacman eating little white dots in their game. Also the police cars that follow and then arrest these drivers are called 'ghosts' in this particular instance.
Person one: 'man that person has got to be wasted, they're driving in the middle of the road!'
Person two: 'dude! they are so playing Pacman right now!!!'
Person one: 'should we call the cops?'
person two: 'naw man, here come the ghosts now.'