A Home Assistant automation to have several switches follow the on-off state of another switch.

SwitchesSync.yaml

alias: Office Lights - Follow Moulding Lights
triggers:
  - entity_id:
      - switch.ofc_moulding_lights
    from: "on"
    to: "off"
    trigger: state
  - entity_id:
      - switch.ofc_moulding_lights
    from: "off"
    to: "on"
    trigger: state
actions:
  - target:
      entity_id:
        - switch.ofc_power_strip_ofc_floor_lamp
        - switch.ofc_power_strip_ofc_led_switch
        - switch.ofc_desk_leds
    action: switch.turn_{{ trigger.to_state.state }}
mode: single