Question

If you have a positive electrical force, and a negative electrical force, what do you expect will happen?

Answer 1

I expect that they will add, and their effect at every location will be the sum of their individual effects at that location.

For example:

If they're acting at the same point and in opposite directions, the effect will be the same as a single force at that point, with strength equal to their difference, and in the direction corresponding to whichever one is stronger.