example restart HA when wemo isn't found

mqtt:
  broker: ***
  port: 1883
  client_id: home-assistant-1
  keepalive: 60
  username: ***
  password: ***

device_tracker:
  - platform: nmap_tracker
    hosts: 192.168.0.1-255
    home_interval: 1
    interval_seconds: 30
    consider_home: 900

ifttt:
  key: ***

notify:
  - platform: pushbullet
    api_key: ***
    name: pushbullet

switch:
  - platform: wemo
  - platform: mqtt
    state_topic: "home/killhass"
    command_topic: "home/killhass"
    name: "KillHass"
    qos: 0
    payload_on: "ON"
    payload_of: "OFF"
    optimistic: false
    state_format:

script:
  restarthawemo:
    alias: "Restart HA if WeMo isn't found after 15 minutes"
    sequence:
      - delay:
          minutes: 15
      - execute_service: notify.pushbullet
        service_data:
          message: 'WeMo not found, restarting HA'
      - execute_service: switch.turn_on
        service_data:
          entity_id: switch.killhass

automation:
  - alias: "Restart HA if WeMo switch isn't found after 15 minutes"
  trigger:
    platform: state
    entity_id: device_tracker.wemo
    from: 'not_home'
    to: 'home'
  condition:
    - platform: template
      value_template: '{% if states.switch.wemo %}false{% else %}true{% endif %}'
    - platform: state
      entity_id: script.restarthawemo
      state: 'off'
  action:
    service: homeassistant.turn_on
    entity_id: script.restarthawemo
  - alias: 'Stop HA'
  trigger:
    - platform: state
      entity_id: switch.KillHass
      state: 'on'
  action:
    service: homeassistant.stop
  - alias: 'Stop restarting HA is WeMo is found'
  trigger:
    platform: template
    value_template: '{% if states.switch.wemo %}true{% else %}false{% endif %}'
  condition:
    platform: state
    entity_id: script.restarthawemo
    state: 'on'
  action:
    service: homeassistant.turn_off
    entity_id: script.restarthawemo