PLT OF A SMA MISTAKENLY APCHED THE WRONG ARPT TO LAND AND WENT AROUND AND DEPARTED THE CLASS B AIRSPACE.

Narrative

I WAS FLYING VFR FROM MADISON; WI; TO WAUSAU; WI; AND USING HWY 51 FOR NAV. I IDENTED AND PASSED STEVENS POINT. SHORTLY AFTER PASSING I CONTACTED WAUSAU UNICOM FOR WINDS AND ACTIVE AND CONTINUED UP THE HWY. THINKING THE NEXT ARPT TO BE WAUSAU I SET UP A PATTERN TO LAND. I NOTICED ON SHORT FINAL THAT THE RWY NUMBER WAS 26 INSTEAD OF RWY 22. I MADE A BALKED LNDG AND FLEW OUT OF THE AREA TO FIGURE OUT WHY. FINDING MY ERROR I CONTINUED TO WAUSAU AND COMPLETED MY TRIP. I FOUND OUT LATER THAT I HAD BEEN AT CWA WHICH IS A TWR CTLED FIELD. TO MY KNOWLEDGE NO OTHER ACFT WERE INVOLVED AND I SAW NO LIGHTS FROM THE TWR. (SINCE I DIDN'T KNOW THERE WAS A TWR I WASN'T LOOKING). I DID NOT SPEND ENOUGH TIME STUDYING THE CHARTS BEFORE LEAVING AND AS A RESULT HAD NO IDEA ANOTHER ARPT EXISTED BTWN STEVENS POINT AND WAUSAU. ALSO THE LAST CHART I LOOKED AT (IT WAS THE HANDIEST IN THE COCKPIT) WAS A LOW ALT ENRTE CHART WHICH DOESN'T DEPICT ARPT TFC AREAS. I ALSO NEARLY ALWAYS FILE IFR ON LONGER TRIPS AND AM USED TO ATC WORRYING ABOUT TFC AND AIRSPACE.