A friend of mine posted a photo of a keychain shaped like a FamiCom controller that just had to have. Takara Tomy released a gashapon set that's part of their Takara Tomy A.R.T.S. line which is usually comprised of miniature figures of various game consoles. These are from the first part of their Nintendo Controller Light series. Featuring the 1-P version of the Japanese FamiCom controller, a Super FamiCom controller, a Nintendo 64 controller and a Wiimote that comes in both white and black version. One of the buttons on the controllers, when pressed, illuminates either a red or orange colored LED.
I initially hard trouble finding gashapon machines that had these and when I did find some, they were already empty. Luckily, there's a machine in the Toys R' Us of Robinsons Galleria. They go for 2 tokens each (120php in total) and from my experience, the most common one is the 1-P FamiCom controller. There's a Part 2 set of Takara Tomy's Nintendo Controller Lights that will feature the 2-P FamiCom controller, a different form of the FamiCom controller that came out with the third body of the FamiCom, an indigo colored Gamecube controller, and Wiimotes that come in white and red.
Takara Tomy A.R.T.S. Nintendo Controller Keychain Lights Part 1 - Wiimote (White Ver)