With paid political ads on television taking about half of the campaign budget in major political races this fall, candidates in Illinois and Kentucky were quick to accept a Paducah, Ky., television station's offer of free air time just before the election.

Fred Paxton, president of WPSD-TV, said he hopes the two-minute spots for Senate candidates in Illinois and Kentucky and the gubernatorial candidates in Illinois will force the candidates to address voters on substance, rather than indulge in name-calling.

The candidates' tapes will be played unedited during the station's 6 p.m. and 10 p.m. newscasts, starting late this month. Terry Reeves, WPSD's news director, said he hopes the introduction to the spots will make it clear to viewers they are not just free commercials but an effort to get candidates to talk about issues.

Paxton said he first made the offer to Kentucky Senate candidates in 1984 and decided to expand it this year because of the station's Illinois audience. He said he has not heard of any other television station making a similar effort then or now.

"This is an exercise in journalism, not generosity," Paxton remarked. The station, which charges $450 for a 30-second political ad adjacent to its 6 p.m. newscast, does not expect to lose any advertising revenue.