The best garbage disposal switch for your household depends on several factors, including concerns about safety, convenience, and any limitations set by your current plumbing set up. Many families with children are concerned about the possibility of a child getting his hand stuck in a garbage disposal while it is in operation, compelling them to seek out switches that are designed to prevent this sort of thing from happening. For others, the main concern in choosing a garbage disposal switch is to make it easy for whomever is doing the dishes to turn on the garbage disposal. It's always a good idea to discuss your options with the contractor who will be installing your garbage disposal.
If you have reasons to be concerned about safety issues, a "batch feed" garbage disposal may be your best option. A batch feed garbage disposal switch is actually built into a stopper for the sink. You must first fit the stopper into the drain and then turn it in order for the garbage disposal to start running. This precludes any danger of someone becoming injured because they have their hand in the garbage disposal when it is switched on. The disadvantage to this method is that there is always the potential for the switch to go missing or to break, rendering the garbage disposal useless until the batch feed garbage disposal switch is is found or replaced.
The second type of garbage disposal switch is the "continuous feed" switch. This type of garbage disposal does not require a separate drain stopper, but is operated via turning on a switch which is either mounted on the wall or an "air switch," which is mounted directly on the sink. One significant danger of a wall switch is that it is easy for one family member to turn on the garbage disposal without being aware that another family member has his hand in the drain. Another disadvantage is that the person who is doing the dishes must disrupt his work in order to turn on the switch. With an air switch, the person who is doing the dishes can turn on the disposal with little or no interruption to his work. He also has the advantage of being able to keep his eye on the switch, which can help prevent the risk of another party turning the disposal on while his hands are in the drain.