200tdi headlights

evening all just wondered if any of you could help me ? I was driving to work this morning and noticed that when i braked my main beams came on, when i took my foot off the brake it went out, slightly confused i put my headlights on and continued my journey. When i set off home it was dark so i didn't know if it was doing the same again till i got home, when i stopped i turned my lights off and pressed my brake pedal and my lights came on, i took my foot off and they still stayed on even though my stalk said they were off, i flicked my stalk backwards and forwards to see if it was sticking anywhere but it doesn't seem to be also i have no rear lights or brake lights ! i thought it may be the earth strap in the engine bay so i removed that and cleaned up the area and connections but to no avail.
Has anyone come across this before or do i have to call an auto electrician out tomorrow ??

cheers Andy