Tier 3 secret, contact exes?

Secret clearance is just a new unknown so likely more stressed than I should be. For secret clearance do they actually contact ex spouses? I know they “can” do anything they want but do they actually contact people including references? If they do contact people is the scope usually 5 or 7 years that they actually go back? I don’t like the idea that I will have a vindictive ex spouse knowing what I’m doing since I haven’t even been in contact with her for 6 years (I was plaintiff in divorce). On a side note, will investigators take whatever one person says or your history and divulge that information to another reference? Here is a plausible example - If person had a bad review/conduct warning at job A back in the day, would the investigator tell job B that the person had that bad conduct review at job A hoping to get more info from Job B? I.e. do investigators tell other references bad things they hear about you along the way? Could be anything, even something an ex spouse says for example.