Hi All, new to the group and happy new owner of a 2002 S8

The boot open warning on the dash is always on, even though it’s shut properly! The lights in the boot don’t work and the alarm won’t set. I think these are all related and have narrowed it down to a micro switch in the boot latch. Does anyone know the part number for this and where I could get one? Has anyone really laced one before? Any advice would be appreciated. Thanks in advance, Alex