I would check the electric isolating switch ( pull cord on ceiling ,or wall switch outside bathroom ). even though the neon light works on the shower .isolate the shower circuit at fuse board or consumer unit before opening switch .look for signs of overheating of cable insulation and loose cable at terminals. if all looks OK ,you then need an electrical multimeter to test that the switch is actually working. you said shower stopped working suddenly. I ASSUME , you used it then turned off the isolation switch ,and next time you went to use it ,put switch on and it didn't work. if so that certainly puts the switch on the top of the list to check out.