add wifi to a tv

No. If the Sharp LC-45GD7U had either an ethernet RJ45 port, or HDMI

1.4 or higher, which include 100MbaseT ethernet in the HDMI connector, it would have been fairly easy to do by adding a wi-fi wireless client bridge radio (sometimes known as a "game adapter"). However, your TV does not have an ethernet port and I can't quite identify what level HDMI port is supplied. I'm fairly sure it's not HDMI 1.4 because those with ethernet on HDMI 1.4 or higher, usually also include an RJ-45 ethernet port.

Spec and features list:

 

Why would adding "wifi" to a TV that doesn't support it do any good anyway? Will it suddenly support streaming AVI's and Miracast, or something?

Call me stupid (I'm fine with that), but a $30 Fire, Chromecast, or Roku would add wifi. PLUS the ability to covert wifi signals into ... like... moving picture shows. And talkies with SOUND! And color even! It the new fad!

</sarcasm off>

-sw

It wouldn't but it's difficult to tell because the OP didn't specify what he was trying to accomplish. I just realized that he might be talking about a Roku or Apple TV player, which plugs into the HDMI port, and requires a wi-fi or ethernet connection to the internet (through a router) to function. That certainly would work.

Yep. That's probably what the OP wanted. Sorry for not reading between the lines. This is what happens when someone asks a question about HOW to do something, without specifying WHAT they are trying to accomplish. It's like asking about how to tie a knot, without disclosing that they're trying to tie their shoelaces. I'll give the OP credit for specifying the TV model number. That's an amazingly rare thing.

It's 1:30AM here. After about midnight, sarcasm, logic, good ideas, and such all become muddled together into an indistinguishable mess.

Drivel: We're waiting for the "big storm" or "atmospheric river" which is suppose to arrive Sunday evening and wreak havoc and clean the rain gutters in this area. I probably should have spent the summer building a Noah's style ark.