I would recommend you sports betting(because that's what I do), but if you are not into sports or anything about betting you can do online casino but I am warning you that some online casino can take a lot in your wallet because you might not want to stop because you are losing big, I also don't trust casinos that much because they are made to take more money rather than you taking more money plus there are chances that you will be a victim of casino rigging which is very frustrating because there was no competition done you were just swindled.
Betting on sports is a good idea. Sporting events take place with a small frequency, so a person always has a chance to stop, pause and possibly stop this activity. Another thing is casino - here you can bet every second and it is pretty hard stop.
As for fraud, I see no reason to play in a casino in which there is no honesty control.