After you click on Stop, select the cubes and your actor. Then, hold Alt and create a copy of all by moving on the Y axis. Now, click on the second actor and pick the upper and lower cubes. Then, select one point light object from Modes | Basic on the left-hand side and place it close to the stage surface between the two cubes. Our goal is to turn on the light when the cubes experience collision and break one of the cube's physical constraints.

Now, click on point light and navigate to Rendering in the Details section and uncheck Visible:

Now, click on Blueprint and select Open Level Blueprint. Navigate back to editor and select your point light. Now, go back to the Blueprint editor, right click on it, and select Create a Reference to PointLight from the list. You will have a curvy box with the PointLight title on your blueprint stage. Now, locate the small blue hollow circle in the top-right corner of your point light box. Then, click and hold the mouse and move...