Hello,
You can create a pattern for this effect. Make a new document 4 px tall and 1 px wide. (width dont really matter since you want horizontal lines).. make a 2 px tall selection on the bottom part of the canvas and fill the selection with black. invert the selection and fill the top half with white. Go to select > select all, and then go to edit > define pattern…
Then go back to the composition you are creating, make a new layer on top of the layer stack, and use the paint bucket tool to fill the layer with a pattern…choose the pattern you just created. Fill the new layer with this new pattern and you will see black and white scan lines. Change the blend mode of the layer (to something like overlay or soft light), play with the transparency of the layer if needed and that should do the trick
hope it helps
good luck
renato