Invisible harness

Hi, I would like to make a happyghast harness invisible when having a special item model or custom model, does anyone know how to do it ?
i have tried to in the ressources pack > models > item > red_harness to do this to try to have a general invisible one but it didn't work
{
  "layers": {
    "happy_ghast_body": [
      {
        "texture": ""
      }
    ]
  }
}