There are two lights in our communal hallway. These are standard lightbulbs and are not halogens fed by a transformer. One is fed from the electricity in my flat the other from the electricity supply in the other flat. There is a two way switch next to each of the flat's doors. One button controls one light and the other button the other light. There is a long delay between pressing the switch by my flat and the corresponding light coming on? By long I mean, 2 - 3 seconds. There is no delay when I turn it off. Any ideas as to why this might be?