how do you create a vertex on intersecting edges?

I know for a fact that these two edges from two different objects are crossing.
I need to place a vertex on the intersection. How can I do this?


Only 2 edges? In that case, I’d do it by hand. [W] --> Subdivide, [G][G] Vertex slide.

If there are more edges, the Intersection add-on will do half of the work for you: