Normally cable modem / routers are quite useless when disconnected from the cable network.
Had the same question been about an ADSL/VDSL modem router that cold well have worked.
Perhaps a TP Link Archer C6 or similar would do the job.
Thanks for your post regarding turning you old hub into a switch/access point.
We cannot say it will be possible, but after a bit of investigation there is a possible solution.
The help page here will give you a rough guide on how to do it. Sorry its a 3rd party website as it is beyond our support scope.
I have seen posts about using a SH2 as a WiFi access point, but it was some time ago. A search of the board may turn it up.