He moved to Hounslow, in Middlesex, with his parents and his older brother Arthur in 1960 at the age of eight, where he got a job helping the milkman, which paid about five shillings.
He was discovered while playing football with his brother in the park by theatrical agent June Collins, mother of Phil Collins.
he had also appeared in episodes of Z-Cars, The Newcomers and George and the Dragon.
Collins enrolled both Jack and Arthur at the Barbara Speake Stage School, an independent school in Acton in West London.
The Wild brothers sought acting roles to supplement their parents' income and, in the autumn of 1964, both were cast in a West End theatre production of Lionel Bart's Oliver!
His alcoholism ruined both his career and marriage to Gaynor Jones, who left him in 1985 because of his excessive drinking.
His mother (Vera Wild) died in 1989 and his brother (Arthur Wild) died in 2000.