core/homeassistant/components/input_boolean/icons.json

{
  "entity_component": {
    "_": {
      "default": "mdi:check-circle-outline",
      "state": {
        "off": "mdi:close-circle-outline"
      }
    }
  },
  "services": {
    "toggle": {
      "service": "mdi:toggle-switch"
    },
    "turn_off": {
      "service": "mdi:toggle-switch-off"
    },
    "turn_on": {
      "service": "mdi:toggle-switch"
    },
    "reload": {
      "service": "mdi:reload"
    }
  }
}