I installed recess lights in my living room 5 total. Jumping one light to the other. The last light has the line going to a existing wall mount with 2 three way switches in the wall already. I cut the wall open wider to hold all three switches including the switch for the line I just ran. My problem is how do you hook up the third switch for the recess light.

What wires are in that existing switch box? Do you know if there is a constant feed in there?

If you ran to a wall mounted light, hook to that and it will operate with wall mounted light.
Do you have conduit or romex?

There was no feed but thank you for answering. I had to run a separate line to an existing power box which I found right below the wall mount in the basement.

Good Deal. So your all set?

I installed recess lights in my living room 5 total. Jumping one light to the other. The last light has the line going to a existing wall mount with 2 three way switches in the wall already. I cut the wall open wider to hold all three switches including the switch for the line I just ran. My problem is how do you hook up the third switch for the recess light.
Do you have 3-way swith or do you have 3 single pole switches. A 3-way consist of 2 switches allowing you to operate a light from 2 locations. If you have 3-way connect ground wire to light, then connect a hot wire to 1 switch, then connect a hot wire from light to other switch, anf last connect the remaining wires. Which would connect 1 switch to the other switch. These are called travelers.

Yes I'm all set. I had to fish the wall but it was easy. My next project is a ceiling fan in my bedroom