How does a recessive allele “show up” to be seen?

Recessive alleles only show their effect if the individual has two copies of the allele.  

Explanation:

Dominant and Recessive Alleles If your allele pair is FF or Ff, you will have freckles. The only way you can escape a freckled face is to inherit the recessive gene from each parent, giving you the ff allele pair. In general, recessive alleles show up in your phenotype only if you have two of them.

sleep paralysis is a parasomnia, events associated with sleep.

sleep paralysis happens when you are in the middle of waking up or falling asleep. it is the feeling of being conscious but unable to move. it definitely involves hallucinations.

i had a friend that had sleep paralysis and he told me a story one time where he was laying in bed and he couldn't move his body no matter how hard he tried and there was someone standing in the corner of his room coming towards him. he couldn't move and you can't "wake up" because you are already conscious. sometimes sleep paralysis can be triggered by frequent waking up during the night based off of multiple trips to the bathroom, or if you had ever been abused, sleep paralysis can start happening from things like that.