[retiredbiker]

That 0097 you see is the character you can't see - it is U+0097 END OF UNGUARDED AREA. If you put the cursor just after one of these in the editor and look down to the bottom right of the screen it should show you the character name.

So it is a little tricky, but you can actually select that invisible character with shift+Left Arrow, copy it, and paste it into the Find box. Then replace it with the em-dash.

There may be other punctuation done with some invisible arcane characters. I have found a very few old books completely punctuated with these bizarre things. I used to be able to "see" these characters on my PC as funny little pictures in some applications, but some update to my OS must have changed something, and they are now invisible everywhere, so it is more difficult.