Authorities conducted a ground search Tuesday near the home of a northwest Georgia 911 dispatcher missing since last week.

Relatives of Theresa Parker contacted the Walker County sheriff's office on Saturday after growing concerned because they hadn't heard from Parker in several days.

Parker, 41, was last heard from about 10 p.m. Wednesday when she talked on the phone with her sister, said Walker County Sheriff Steve Wilson. It was Parker's habit to talk to her mother or other relatives at least once a day.

"Obviously this is totally uncharacteristic for her. ... She's always been a very punctual type person who is very dedicated to her job, her family," Wilson told FOXNews.com on Tuesday.

Police received a tip Monday night that caused Wilson to deploy searchers around 11 a.m. to the area around Parker's home. They are focusing on two to three parcels of property, he said.

"We don't know that this will turn out to be a good lead or not until we run it out," Wilson told FOXNews.com, adding that search and rescue personnel, volunteer firemen and other officials are involved in the so-called "grid search" common with missing persons cases.

A command post is operating at Corinth Baptist Church in Lafayette.

No one at the 911 dispatch center noticed her absence, Wilson said, because she was scheduled to be off work. But she failed to show up Monday for her 7 p.m. shift.

"We knew then, we're just very, very concerned at this point because this is just not typical for her," Wilson said.

Wilson said officers are canvassing her neighborhood and interviewing family, friends and co-workers. So far, authorities have no clues why Parker disappeared.

The case was turned over to the Georgia Bureau of Investigation because of the close ties between Parker and the local authorities, Wilson said. She has been a 911 operator for about 15 years, and worked as a police emergency dispatcher before that.

Wilson, who knows her personally, described her as a "very knowledgeable, very thorough employee, a very likeable person."

Parker's husband Samuel is a police officer with the Lafayette Police Department. The two were separated and were not living together at the time of Parker's disappearance.

Wilson said Samuel Parker is not considered a suspect and has been interviewed two or three times by the investigators handling the case.

"He's been cooperative so far, so far has answered our questions," Wilson said. "At this point I would not classify him as a suspect, he's certainly been cooperative but on the flip side, we have not eliminated anyone as a suspect, either."

Parker's car was found at the home she shared at her husband before the separation. Parker was still living in the home but was planning to move to a neighboring town. Samuel Parker was staying with a relative, Wilson said. The GBI has not yet reported any unusual credit-card activity or any other suspicious activity to local authorities, he added.

When asked if he has any reason to believe Parker won't be found alive, Wilson responded: "Scientifically, no. Obviously we're deeply concerned we may find the worst because of a number of days now that have elapsed but we're still hoping to find her out there somewhere in good health. ... But obviously we have to be realistic here and know that as time passes on, the probability is not as good for her."