Garbage disposal install - runs on off, trips breaker when switched to on
You incorrectly wired the switch into this device. What you've created is an always on device and a short in the middle of the circuit:

      Black --------+-----------+
                    |           |
line              switch      disposal
                    |           |
      White --------+-----------+


In this scenario, when the switch is flipped, you create a short circuit that trips the breaker, and there's nothing preventing power from always going to the disposal.

Instead, what you need is to switch the hot, so that power is turned off to the appliance when the switch is opened. Note, you don't switch the neutral since that would result in power going to the appliance and becoming a shock hazard should anything make a path available to ground.

      Black =---+-switch-+------+
                                |
line                         disposal
                                |
      White --------+-----------+