I feel I need to clarify. Yes, this stuff does happen but other than missing prints I have not had it happen for a while. It was quite common on our jobs in the 80's and 90's. Other than changed wires (making up dir lanterns down or turning buttons over) which were done by mechanics I know, the jokes mechanics play, the integrity of the men/women in the field is usualy of the highest levels and I am proud to be in this trade. If I offended anyone I apologize.