{
  "tile_processors": [
    {
      "type": "leveled",
      "levels": [
        {
          "level": 0,
          "type": "weighted_target",
          "target": "ispawner:spawner",
          "output": {
            "ispawner:spawner{ Inventory: { Stacks: [ {id: \"minecraft:silverfish_spawn_egg\", Count: 1} ] } }": 1
          }
        }
      ]
    }
  ]
}