Early Shelley Long commercials online
These were for a furniture store in Chicago and apparently aired years apart. So she was probably their spokesmodel for several years. She was apparently cast in a stereotypical "homemaker" role. A bit different from Diane Chambers...
http://www.youtube.com/watch?v=daGz-5KO56Y
The funny thing is this next one was aired during a May, 1983 Siskel & Ebert show, the year after she starred in Night Shift and started on Cheers. Perhaps they pulled one from the archives or she was still under contract to do these. They didn't bother mentioning her name or turning it into any kind of celebrity endorsement spot. Her commercial starts at 4:06 in this video:
http://www.youtube.com/watch?v=a0vsiNSTLyI