Man Finds 6 Decades Old Envelope While Repairing An Arizonian Ranch Whose Contents Leave Him Aghast

The name written in the letter was Betty Klug and nothing else was mentioned on the envelope. There was no mention of the time or date on which it was written and to whom. He couldn’t find a single clue to know about the owner. As he had already promised himself that he would maintain the secrecy of the envelope hence he restrained himself from opening the envelope. Would he be able to resist his temptations or else would open it?