Use of "Might" and "Might not"

I know "Might" and "Might not" means the lack of certainty, but is there an implied probability in the use of these terms?

In other words, does "I might be coming" imply that "It is extremely likely I will be coming" or is it a case of "It is likely that I will be coming" or moving down even lower "It is feasible that I will be coming" ?

Is the situation identical with the use of "Might not" ? When someone says, "I might not be coming" what approximate probability level are we talking about regarding their "not coming"?

I realize this is a basic question -- sorry about that; Just was not sure about the usage.

Solution 1:

The word "might" is used to express possibility in favor of something. Negating it expresses the opposite. Technically, "might" allows for the possibility of "might not" but it doesn't necessarily offer that as a possibility to be considered.

I might come to your party.

This gives the listener some hope that you will attend the party.

I might not come to your party.

This alerts the listener of the sad possibility that you will not attend.

Solution 2:

I read "I might be coming..." to express the possibility but not necessarily the likelihood of attending, and "I might not be coming..." to express the opposite. If I wanted to express strong possibility, I would say "I will probably [not] be coming...". A lot depends on context; for example, "I might be coming, assuming I grow a second head" is not the same as "I might be coming, unless I get one of my infrequent migraines".