Question: Can we configure wireless router as an access point only?

Yes!! You can do that! This is especially useful if you have limited wireless network coverage in your home and need some ways to mitigate it, or simply want to add wireless connectivity capability to your wired home network.

Reusing and reconfiguring the unused wireless router as an access point is a simple way to expand wireless coverage for better user experience with minimal effort and cost. With this approach you don't need to purchase additional wireless access point or wireless network extender to tackle limited wireless network coverage issue anymore which means you are going to save more.

In addition, this access point setup is much simpler than configuring a wireless router. Simply put, what you need to do is to connect this wireless router’s LAN port to home router’s LAN port with crossover cable (the home router is the main Ethernet or wireless router used in your home). After that, proceed to configure an IP address, netmask on this wireless device (we just treat this wireless device as another component on your home network). Finally configure SSID, wireless mode, encryption and other wireless settings and then it should work.

Ignore the WAN port of wireless router, you are not going to use it. Also you need to disable the DHCP and other WAN related configurations as well (or just don't configure them). Once the configuration of this wireless device is completed, you should be able to connect your laptop or mobile devices to this new wireless network by connecting to the newly created SSID.

Check out here on how to do it in details if you need more guidance.