My colourful ancestor was my paternal grandfather. I only learned this recently in the couple of years before my Dad died, but he had a big car in the 1920s when very few people had them and working class sons of coal miners definitely didn't. Dad couldn't afford a car in the 1960s. My grandfather also owned a greyhound (I mean one that raced, not a pet) and was always at the dog track. His real job was as an insurance collector, but Dad hinted at something dodgy and my suspicion is that he was part of some kind of illegal betting ring. Going door to door each week collecting premiums would be ideal cover for taking illegal bets (I believe that off-course betting was illegal until after the war.)
He never became wealthy. Being badly wounded in the First World War can't have helped, but he was much better off than Mum's side of the family and he invested wisely by buying a few cottages so had the rent from them as well as the wage and whatever he was earning on the side.