Ray Tracing: Transparent/invisible but emissive object

I’ve been working with GitHub - SaschaWillems/VulkanPathTracer . I want to add invisible lights to the scene. Basically, an invisible light source. Currently I can add an object and make it emissive so it acts like a light. But how to make this object invisible?
Hit shader looks like this:

    if (material.type == 1) {
            // Light source
            const vec3 lightColor = vec3(255.0) / 255.0;
            payload.color = lightColor * 15.0;
            payload.scatterDir = vec3(1.0, 0.0, 0.0);
            payload.doScatter = false;
        }