Hi. Turned power off to change a socket front. Turned off at breaker not the RCD or mains. Checked that socket was dead got these readings Line to Neutral 0 volts , live earth 30 volts , neutral earth 30 volts. This is an old French house on a 3 phase supply Split at consumer unit and then each board of which there are 9 are using one of the phases per RCD. We had some shared neutral issues on the lighting circuits when we replaced all the boards. Why am I seeing voltage from neutral to earth and live to earth ? Any help would be appreciated.