I used to completely freak out about mice. My old useless cat brought one inside but had no idea what to do with it and lost it behind the fridge. DH was away on a business trip and I had to call my Dad to come catch and dispose of it -- It was either very late or very early, and I was so incoherent on the phone he thought it was a dire emergency... until he understood and then he laughted at me, though he did arrive shortly.
I know where my irrational fear comes from though -- when I was younger, I went up to my cozy bedroom to go to bed and there was a mouse perched in the middle of my pillow!
Had morbid fear of any animal on my pillow ever since -- I wouldn't even put stuffed toy animals on my pillow... Until the said useless cat first came to me as a kitten and claimed my pillow to snuggle up in.
After said cat passed after long 18-1/2 years of life, we got some gerbils because I couldn't even think about getting another cat for a long while.
They were only with us for a few years (short life span, you know), but mice and mice turds no longer bother me (though I still would rather not have them in my house)
And we adopted a couple of barn kittens shortly thereafter.
. One of them is a good mouser.