// Sets the position to be somewhere inside a sphere
// with radius 5 and the center at zero.

transform.position = Random.insideUnitSphere * 5;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Example() {
        transform.position = Random.insideUnitSphere * 5;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Example():
        transform.position = (Random.insideUnitSphere * 5)