Electrical fault

My Seat Cordoba has developed an annoying fault as follows. The centre consol features a display for the heating and radio etc, when i put the lights on this ligts up red as does the speedo etc. The problem is when I switch off the lights all the displays switch off apart from the radio and heating display, this just flashes on and off and eventually stays on even though the lights are off. This is a definate fault. How wouyld I go about fixing this and would it be easy?. Or if I took it toi an auto electritrician how much would that cost. Thanks in advance Dave