I was wondering if anyone could give me some advice on how to fix this:

Most of the time my boot light does not work. Some very rare random occasions it does come on. Last year in Skoda they said they cleaned some sensor or connector and it worked for a while now its back to normal.

Please can someone help me out on what to do? I have had a look and nothing is jumping out.

Probably a switch / connector in the boot latch mechanism if the actual light unit itself is OK.