Someone that is quite obviously not right, appearance and or body language. Possibly bad fashion sense, but a wrongin is not judged on class, one could be a poncy toff or a down and out bum. They just look wrong. Equally it could be someone who does things that are deemed not wholesome or correct. They could be stingy, they could be devious in their ways, they could have a limp hand shake. Two friends can often walk down a crowded street and both will be able to pick out the same wrongins without need for mutual consultation.
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.