Aliexpress
Here are coupons that you can use.
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – BlitzWolf BW-SS11 Dimmer Light Switch [EU] (-3 USD)
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. There is one great coupon!
Link: Banggood product page
Coupon (13.99 USD): BG0c8eec
(CouponsFromChina.com tip: this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG2e54a6, BG32adec, BG064673, BG4b6d84, BGSHE15, BG7b998d, BG11393f, 13f142, BG909d56, 6GSGIT, BGD11013, BGB5013, BG52017b, BG1f4384, BG179bf5, ADMITAD2212, BGSmart6, BG1f1ddf, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BGJUNEGSG9, TTSUMMER8, Cuponation9
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – BlitzWolf BW-SS11 Dimmer Light Switch [EU] (-3 USD)
Price history and price alert
Price history (for all/most countries) for BlitzWolf BW-SS11 Dimmer Light Switch is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).