Harbor Freight sells a pretty decent safe for secure storage of selected items in the home, their item number 93575. With the right discount coupon the cost was about $24, just a couple of dollars more than their smaller safe but, IMO, of much better quality/construction.
I wanted to use this for a discreet situation where the safe’s very loud keypad beep would be a distinct disadvantage. Others had posted solutions on the product review pages that involved totally silencing the beep through squirting super glue into the speaker or de-soldering it from the board.
Mine is a simple solution with what I believe are two distinct advantages: ability to adjust the volume to retain some of the feedback capability, and reversibility – the ability to undo the change and return the safe to factory condition in case you’d need to return it for some reason.
What I did was to insert a small screw into the opening in the speaker housing, which I screwed down carefully and slowly until it reached the volume level I wanted. This worked great and has remained the same for several weeks now. See the following photos for how to do it.