RaycastHit always returns 0

I'm trying to move a blood prefab (a decal) to an enemy's feet when they die. The old script I had (commented out in the Start() function) simply drops the y coordinate to 0. However, I want to use raycasting to drop the prefab to the nearest collider, within 2 units. Otherwise, the prefab should be destroyed.

 using UnityEngine;
 using System.Collections;
 
 public class PuddleDown : MonoBehaviour
 {
 
     // Use this for initialization
     void Start()
     {
         //transform.position = new Vector3(transform.position.x, 0, transform.position.z);
     }
     void Update()
     {
 
         RaycastHit floor;
 
         Vector3 down = transform.TransformDirection(Vector3.down);
 
         if (Physics.Raycast(transform.position, down, 2))
         {
             transform.position = new Vector3(floor.point.x, floor.point.y, floor.point.z);
         }
         else
         {
             Destroy(gameObject);
         }
     }
 }
 

The problem is that floor.point is always 0, no matter where the AI is. I don't use raycasting a lot and I have no idea why this is happening. Can someone help me?>