Hello Mormit.

These switches can be serviced, but it depends on the skill and dexterity of the person doing it. If you are not used to the stress, and frustrations of working on tricky little mechanisms, then this is your chance to improve, OR 'leave it alone' as the case may be.

These switches are wide-open to the ingress of grit,and fluff, and all that is unwanted on switch contacts.

When I go inside one I usualy find it 'like the bottom of a bird cage', very poor thinking, and bound to cause problems 'down the line'.

Recently, I removed a tiny ball of aluminium foil from an Easter egg from inside a switch,it was all mixed up with the contacts, and had it not been for the dog hairs holding it in place,and the insulating layers of dead human skin,and the desicated food; it could have burnt a window motor out, maybe.

Hope this helps somehow.

Best regards. Howard. Isle of Skye.