Amazon offers Prime members the Leviton Vizia RF Plug-In Appliance Module in White, model no. VRPA1-1LW, for $23.99 with free shipping. (Non-members can spend $49 to qualify for free shipping; otherwise, shipping costs $6.65.) That's the lowest total price we could find by $6. It's compatible with Alexa and provides a grounding receptacle for lamps and appliances.