Solutions accompanied by Aha!-experiences are called insights, or, if they are wrong, false insights. Classical theories cannot give an explanation for false insight because they consider Aha!-experience and other metacognitive feelings just as side effects of the cognitive processes. From this perspective, dissociations between cognition and metacognition are impossible. According to the signal theories of insight, metacognitive feelings, including Aha!-experience, form in two stages. Finding a solution on the unconscious level causes a non-specific emotional signal that is attributed by consciousness to any process or task. In this case, false insight and other dissociations between cognitive and metacognitive processes appear because of the misattribution of the signal. The current work tests this hypothesis. We suggested that solving an interfering problem unconsciously would lead to false insights or higher feeling of knowing ratings. We created a method of the false semantic hint to simulate this situation in the experiment. The problems were anagrams with one solution and one word shorter by one letter inside them. The false hints were pictures that referred to shorter words inside the anagrams. We found that participants tend to make more intrusion errors after this type of priming. This proves our method to be working and means that the signal from an interfering problem might be attributed to the main one. Also, the feeling of knowing ratings after intrusion errors were higher than after omission errors. This result can be interpreted as an aftereffect of the initial metacognitive signal and a possibility of its repeated attribution.