It should work, yes, but just like wiring your computer directly to a cable modem, its very unsafe and insecure. You really want to have a hardware firewall/router. With them being so cheap nowadays, there really isn't an excuse not to get one. Not to mention you can only connect one computer at a time without one.
Mr. Criccio is correct, you should add in a router for security as well as so you can hook up more than one machine or device at a time.
You can hook your router up to the modem and from there cable your wireless access point to your router and then you should be able to use the WAP however you want. I did just such a setup today when my dad's Linksys router crapped out and I gave him my Dlink 655 router that I'm not currently using. He he had the Linksys wired to another Linksys inside the house and so all I really had to do was just remove the wires from the crapped out Linksys to the Dlink and since the working Linksys was already configured as a wireless access point, all I really had to do was set up the wireless on the Dlink then power off/on the Linksys and it worked.
Took only a few minutes to do too.
You shouldn't have any problems setting up such a configuration.
just remember this, when you cable your router to your WAP, do NOT cable from your router to the WAP's WAN interface, internet won't work that way (as far as I know), cable it instead into one of it's Ethernet interfaces (LAN ports).