How you find an Object

How you find an object after you delete and instantiate it again ?

This is the error Im getting

MissingReferenceException: The object of type ‘Transform’ has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object.

a better method could be to instantiate just once at the beginning and turning it off/on when required rather than deleting it… both delete and instantiate are costly…