Does impurity transfer by touch if a person doubts the impurity of a place, garment, or body, or if a wet impurity has dried?

We fear that your question may stem from obsessive doubts (waswasa), and we warn you against giving in to them. The basic principle is that impurity does not transfer merely by doubt, whether it is dry or wet, and you are not required to investigate its transfer. You are at liberty to act upon the principle that it does not transfer. Some scholars hold that wet impurity does not transfer to a pure object that touches it, under certain conditions.