Does this effect not work or am i doing somthing wrong?

                    Vector3 position = char1.transform.position;
                    Vector3 offset = new Vector3();
                    Effect.server.Run("assets/content/effects/electrical/fx-fusebox-sparks.prefab", char1, 0, offset, position, null, true);​

It's something about that particular prefab. I replaced the prefab string with yours in my working code and it didn't work. If you look in the console, there's a warning.

Not all prefabs are something you can from from the server. I'd suggest trying a different one.