What evil lurks in the hearts of men the "Shadow Chasers" do not know. Nor are they likely to be around long enough to find out. ABC premieres its aspiring dead ringer for "Ghostbusters" at 8 tonight on Channel 7, and the shamelessly padded two-hour debut proves at least as frozen a waste as Antarctica itself.

However, there have been TV series this bad that had no saving graces at all, and "Shadow Chasers" is at least an improvement on those. Its redeeming moments are provided by Dennis Dugan, who is endearingly bananas as one of the titular spook sleuths on the (shaky) premises. Dugan, perhaps best remembered in television terms for his four appearances as the spindly but stalwart Captain Freedom on "Hill Street Blues," makes a lark and a romp out of his role here: Edgar Benedek, opportunistic reporter for a supermarket tabloid, prolific author of quickie paperbacks and quintessential bad dresser.

Kenneth Johnson, who wrote and directed tonight's pilot, and made his last TV splash with NBC's grade-Z "V," hasn't given Dugan enough to do or to be, but Dugan wrings the last happy drop out of this lovable loser anyway. He bops through the adventure-comedy with the sort of snappy sang-froid that Bob Hope used to exhibit in comedy films about hapless schnooks playing detective.

The schlemiel reporter is teamed on ghost-hunting exploits with Trevor Eve as a semi-stuffy professor dispatched by the "Georgetown Institute of Science." Sturdy old pro Nina Foch is saddled with the role of the institute's director, the one who sits in Washington and issues directives. All that's really seen of Washington, as might be expected, is a montage of handsome aerial views under the opening credits.

On the premiere, the special effects are not so much low-tech as sub-tech. Investigating the mysterious death of a small-town dabbler in the occult, our nominal heroes dodge falling bookcases and tumbling statues and that sort of thing. Then there's the cheap payoff in which it's revealed all the paranormal telekinesis was really master- minded by a computer. Oh, groan.

All the fun on the show is contained within the opening screwball scene set at the offices of the tabloid (where a fire-juggling swami sets off the sprinkler system to the delight of the roller-skating messenger lady) and in Dugan's droll cool jerk routine. This guy doesn't just whistle past the graveyard; he tap-dances. He's a life-support system for a program that, alas, begs to be put out of its misery.