hey, i think you can try code below, i found it a year ago from the internet, and used it in my little balloon game

Just drag it onto the camera, I added some public functions for accessing from other code, like call Shader(1.0f) to shake it.

but for testing, you can just Play the scene, modify shake attribute see what's happen (make sure the Cam.go = true;)

hope it's helpful!

using UnityEngine;
using System.Collections;

public class Cam : MonoBehaviour
{
    // Transform of the camera to shake. Grabs the gameObject's transform
    // if null.
    public Transform camTransform;

    // How long the object should shake for.
    public float shake = 0f;

    // Amplitude of the shake. A larger value shakes the camera harder.
    public float shakeAmount = 0.7f;
    public float decreaseFactor = 1.0f;

    private bool go = true;

    Vector3 originalPos;

    void Awake()
    {
        if (camTransform == null)
        {
            camTransform = GetComponent(typeof(Transform)) as Transform;
        }
    }

    void OnEnable()
    {
        originalPos = camTransform.localPosition;
    }

    void Update()
    {
        if (go)
        {
            if (shake > 0)
            {
                camTransform.localPosition = originalPos + Random.insideUnitSphere * shakeAmount;

                shake -= Time.deltaTime * decreaseFactor;
            }
            else
            {
                shake = 0f;
                camTransform.localPosition = originalPos;
            }
        }
    }

    public void Go(bool stat)
    {
        go = stat;
    }

    public void Shake(float sec = 0.5f)
    {
        shake = sec;
    }
}