Paddy and Mick are working on a construction site, "paddy" says mick "am gona pretend am mad so i'll get sent home". So paddyclimbs the rafters hangs upside down and shouts "AM A LIGHTBULB", the foreman sees paddy and shouts "get down te hell, pack ur tools and go home, yer mad". Mick starts to pack up as well and the foreman says "where u going"? mick replies "well i can hardly work in the bloody dark can i"?
