Custom Inspector: Targets & GameObjects

Hello, I'm having trouble figuring out how to get and edit gameObject data from the selected targets. I basically want to enable and disable certain children of the selected gameobjects depending on an int value on a script inside them;

I serialized the targets which I used to get the int value - that works

  m_Object = new SerializedObject(serializedObject.targetObjects);
  m_TunnelState = m_Object.FindProperty("Slider");
 (Then use "m_TunnelState.intValue" to get int)

But I can't seem to get the gameobjects in a similar way, to do the normal stuff like "gameObject.active = false"

I already tried the following, but clearly it is wrong:

 FloorTile[] Current = (FloorTile[])m_Object.targetObjects;
         foreach(FloorTile Tile in Current)
         {
             Debug.Log(Tile.name);//test
         }
   

('FloorTile' is the script which this editor is being used on)

I get 'InvalidCastException: Cannot cast from source type to destination type.' when selecting and deselecting multiple gameobjects

thanks, sorry for the long post