It takes only a minute to walk between these two stations, but what would happen if I went to the ticket office at Wigan Wallgate and asked for a train ticket to Wigan North Western? They would say walk it, but what if I insisted I wanted to go by train? Would they sell me a ticket under the "buy a ticket to any station on the rail network" premise or would they just say I'm daft and to walk it? I know this is an unusual question and it would never happen for real, but would like to know what would happen if I tried.