Router not connected to the Internet

GoodyATC wrote:
I would like to play movies on my television from my phone. However, there exists (as far as I've found so far) no way to convert an hdmi or component cable to my phone or tablet (Samsung galaxy s7 or Tab4 7.0). The available converters stop working at s6. I did get a Samsung converter (for which I thought I hit paydirt), but it has a micro USB attachment that ONLY fits a Samsung TabS.
So, everything I've read said attach it wirelessly. However, I wasn't planning to add a wireless router, that connected to the Internet) to the RV.
My question is, has anyone used a router to setup a private wireless network, that doesn't connect to the Internet, on their RV? I don't need Internet access for the wireless network (I can use phones capabilities to do that), but I would need the wireless to connect the devices on the RV that ALREADY have the media on them.
Also, if I did have Internet access (which I know could be "spotty"), I could stream "wirelessly" from my phones or tablets.
Anyone done that? What router would you recommend?