I imagine you should just be able to replace just the hazard light switch.
Im not sure how easy it is to replace as I've never done one but I would imagine it would be a case of prising up the whole module your describing and releasing the locating lugs from below for the hazerd switch after taking off the electrical connection.
Might be worth getting in contact with gonescenile on the forum as he is breaking a Laguna.....(look in the for sale section) Guests cannot see images in the messages. Please register to forum by clicking here to see images.
Failing that get down to a breakers / scrapyard.