Roger. With the Zapper, you have to make certain that no crumbs or bits of anything get lodged under the electrical "plate."
Turn your Zapper on its side, entrance/open side down, give it some taps to dislodge any foodie bits. Zapper shouldn't "read" (red light blinking) that it contains zapped mouse/woodrat, unless something is setting off the plate sensors. Remove batteries and oh-so gently wipe off plate with damp cloth, too.
If this false alarm keeps happening, return unit to seller, as it is defective. Remember: one set of batteries should take care of at least five mice/rats. Sorry you have to do this.
Again: remove any food source that is luring in rodents. Put everything in metal or glass or in refrigerator/freezer. Good luck.