That all devices like this don't turn on the WiFi when Ethernet is in use that may not be good enough for you. It appears you may have to forget Roku?
I have an older Roku, that does not have wifi capabilities. I am using it to stream content to my HDTV, via ethernet. I want to keep this set up, & when Roku recently informed me that I would need to upgrade to one of the newer models, to keep channel compatibility, they recommended the Roku 2, since it can be connected via ethernet also. I let them know that I wanted NO wifi at all...I have small children in my home, & I do not want anything that will emit any kind of wifi signal. I don't use my cell phone in the house, I don't use a microwave, & I don't have a cordless phone, etc. I understand that all electronics will emit EMFs, but I am specifically concerned about wifi signals. Roku customer service told me that there is no manual shut off for the wifi, but that I can use it via ethernet, & that the Roku 2 doesn't have the same wifi remote that the Roku 3 has, so I wouldn't need to worry about that, either. However, there is some conflicting information about whether or not the new Roku 2 would still emit a wifi signal, even if it's connected via ethernet. I can't seem to get a straight answer out of customer service & I really need a definitive answer about this one way or another, I need to know for sure if it would emit ANY kind of wifi signal, or not? Any help at all would be so greatly appreciated, thank you so much!