Another prevention note: I must have learned this from the old Julia Child TV shows, to put salt in the palm of the hand first, then add cautiously. I have seen people shake from a container, only to find that the screen is loose (for example), leaving a pile of salt instead of the right amount.

not that I"ve ever found.

The moral of the story is "taste as you go". You can put salt in but you can't take it out. Depending on what sauce, you could add more of the ingredients you used in the first place to increase the volume; eggs, butter, tomatoes etc.

Try putting in a peeled potato or two. Leave it whole or in large pieces that you can then retrieve from the sauce. The potato will pull out some of the salt. Good luck!