Near Rhymes:
* Blight: This word means a disease that harms plants, but it can also be used metaphorically to refer to something harmful or destructive.
* Slight: This word means small or insignificant, but it can also refer to a danger or threat that is not immediately obvious.
Slant Rhymes:
* Plight: This word means a dangerous, difficult, or unfortunate situation. While not a perfect rhyme, it shares a similar vowel sound and consonant pattern with "peril."
You could also use words that are synonymous with "peril" and rhyme with "light":
* Danger: This word means exposure to harm or risk.
* Hazard: This word means a source of danger.
* Threat: This word means a danger or a warning of harm.
Ultimately, the best word to use will depend on the specific context of your writing.