I think the Bealtaine fire traditions have entered the popular consciousness enough that a good number of people know they exist. There are even big music festivals built around them. But have you ever questioned why they fires exist?
May eve and the Bealtaine festival are times when the Irish version of Hollywood voodoo is at its most potent. Its not just a time for curses like Piseog Bags that are designed to kill. Its a time for stealing the power of creativity, beauty, luck, fertility you name it and it can be done consciously or unconsciously.
Consciously people can bury raw eggs in your hey or any produce of your business to take your profitability. Doing that they wont just curse you to fail theyll also steal your success for themselves. Someone might bury raw meat on your land to destroy your home as it stands never mind the future.
Unconsciously its an auspicious time so taking something from a house or bringing it in is a danger. If you turn up at someones house at this time of year and theyre really into folk trad they might run you off.
More than just a time for piseogs its a time when the fairies are at their most active. The fairy wind and the fairy dart bringing acute and prolonged sickness respectively are a danger. The fire traditions exist as a preventative for all those things. New age people tend to celebrate bealtaine but in folk culture its a time of high stress.