A blueprint that turns on the selected switches when the alarm is disarmed.

disarmed_switch_on.yaml

blueprint:
  name: Turn on switches when the alarm is disarmed
  description: A blueprint that turns on the selected switches when the alarm is disarmed.
  domain: automation
  input:
    alarm:
      name: Alarm Control Panel
      description: Select Alarm Control Panel
      selector:
        entity:
          domain: alarm_control_panel
    switches:
      name: Switches
      description: Select one or more switch to turn on
      selector:
        target:
          entity:
            domain: switch
trigger:
- platform: state
  entity_id: !input 'alarm'
  to: disarmed
action:
- service: switch.turn_on
  target: !input 'switches'