The Lutron Aurora smart bulb dimmer is the best solution I've found to cover up an existing switch. Covers it very nicely, is extremely easy to install, is pretty easily removable, and
60-400W 1 Gang 2 Way Zero Cross Rotary Dimmer - AU-DSP400X
Lutron Aurora: A Smart, Simple Dimmer Switch for Philips Hue Lights | Tom's Guide
Lutron Aurora Smart Bulb Dimmer Switch review | Best Buy Blog
Lutron Z3-1BRL-WH-L0 Aurora Always Ready Smart Bulb Dimmer – Ready Wholesale Electric Supply and Lighting
Aurora Smart Bulb Dimmer Switch | Lutron
Lutron Aurora Smart Bulb Dimmer Switch for Philips Hue Smart Bulbs, White (Z3-1BRL-WH-L0) Z3-1BRL-WH-L0 - The Home Depot
Lutron Aurora Smart Bulb Dimmer Switch for Philips Hue Smart Bulbs White Z3-1BRL-WH-L0 - Best Buy