Have a custom mesh of a ceiling lamp with an emissive map to illuminate light up when light is on. As you knoqw this map will illuminate light regardless of the lighting in the scene.
I have a class blueprint with that light and I need to toggle its Brightness with a timeline. (Flickering light.) I know how to do so with a light but not with the emissive map of the light object.
Here’s how:
In your material, create a multiply between your emissive texture, and your shader. Attach a scalar parameter to this multiply and give it an appropriate name and default value (something like lamp_brightness).
In your blueprint, in the Construction Script, add a Create Dynamic Material Instance node, and point it to your lamp texture. Promote the output of that node to a variable, and give it a name.
In your event graph, when your light is triggered, you can use Set Scalar Parameter to change the value of the named scalar parameter on the fly. (NB: The below graph is slightly different, since I’m controlling my lights with a Matinee, but you should be able to figure out what to do…)
Hope that helps 
I got it. Works like a charm. Thank you.
It sounds like your doing the same thing I’m trying to do (control an emissive map using the matinee) and I was wondering if you could go a little more in depth with regards to how you do that as I’m really struggling 
Thanks