Otherwise

The otherwise property is the automation code that is executed when a rule is triggered and guards are not satisfied. This property accepts a block of code and executes it. The block is automatically passed an event object which can be used to access multiple properties about the triggering event.

Event Properties

rule 'Turn switch ON or OFF based on value of another switch' do
  on_start
  run { TestSwitch << ON }
  otherwise { TestSwitch << OFF }
  only_if { OtherSwitch == ON }
end