However, standalone/dedicated WAPs tend to be overly expensive. It’s usually far more economical to buy another wireless router and use its WAP. Every consumer grade wireless router is actually an integrated device consisting of a switch, WAP, and router. We call them “routers” to keep things simple. But nothing says you MUST use all the features all the time. You can use the switch alone, or use the WAP alone, or use the switch + WAP but no routing, etc.
Knowing that, you could grab a cheap $10-20 wireless router (sometimes you can find a junk one from work, a friend, even the local thrift store for next to nothing). You would reconfigure that router to use a static IP in the same network as your present router (e.g., if your present router is 192.168.1.1, then perhaps make the new router 192.168.1.2, just so long as that IP is not being used elsewhere), disable its DHCP server, and connect the routers LAN to LAN.
You might also want to consider a WAP w/ *wireless* bridging capabilities.
For now I’m not going to get into such details since it gets more complicated. It’s only important to know that while *any* WAP can be bridged over wire to your wireless router, that’s not necessarily the case w/ wireless bridging. So if you believe you would want/need wireless bridging as well/instead, that’s another discussion.