Name what changed
Give the unit model and the switch or button information if available. Say whether the change followed sink, worktop or electrical work.
Check compatibility through assessment
A professional can consider the actual control arrangement before proposing work. Do not bypass the switch, defeat a batch-feed mechanism or rely on another model's wiring advice.
A useful distinction
A separate air-switch accessory may have its own reference, distinct from the disposal model. Both can be relevant, and neither should be invented from a similar photograph found in a product listing.