Hello,
Thank you for your message.
If your family were Catholic, the place to look is the baptismal register for Aglish, which begins in 1837: https://registers.nli.ie/parishes/1088. It's possible, if unlikely, that an earlier baptismal register survives. You could contact the parish and ask, on the off-chance (contact details here: https://www.waterfordlismore.ie/parishes/?parishID=11). If you are unsure of the parish, the best place to look would be Roots Ireland (https://www.rootsireland.ie/), a subscription site which enables you to search Catholic and Church of Ireland parish registers from across Ireland. While it is by no means comprehensive, it should give you a rough idea of how many Michael Miskels there were in Ireland in that time period. Spellings vary considerably in parish registers, so make sure to use spelling variants; in fact, the same goes for all records.
It would also be worth consulting Griffith's Valuation - http://www.askaboutireland.ie/griffith-valuation/ - and other land records on the National Archives genealogy website: https://www.genealogy.nationalarchives.ie/.
Civil registration of births, deaths and marriages was introduced in 1864. If Michael lived that long you might be able to find a record of his death. irishgenealogy.ie enables you to search these records. It's very useful, but not comprehensive.
Wishing you all the best with your research,
Cian
