Need to turn on and off electrical devices on the net? I use the Rabbit Semiconductor products. Connect and access like any IP device, except it is designed for exactly what you want to do. You will need some electronic experience to assemble your working product. It comes as a "core module" with a bunch of TTL compatible pins, but the rest you must construct. That is no problem here.
The RCM2100 is the one I use. Has web server, form processor, etc onboard. The smallest web server I have seen so far! Smaller than a credit card.
They also have products that convert ethernet to RS232 format, but I have not used those.
I think this answer (not your question) may be off-topic for this forum, tho...
I am in no way connected with Rabbit Semiconductors. I just like their products.