Firefighters in Massachusetts are warning parents about a viral challenge circulating on the social media app TikTok.
It's called the "Outlet challenge."
It involves partially inserting the plug of a cellphone charger into an outlet, then sliding a penny down the wall onto the exposed prongs.
The result, sparks and damage to the electrical system.
In some cases, it could cause injuries, electrocution or start a fire.
At Plymouth North High School on Tuesday, two students were caught performing the prank.
Two electrical outlets were scorched.
The State Fire Marshal's Office says there have been incidents at others schools, one which led to a fire.
The students involved could face criminal charges.
“The electricity propels the charges and the coin, its molten metal at this point, outward, it could easily get you in the face, get you in the eye, could cause you clothing to catch fire," Chief Ed Bradley said.
Firefighters are urging parents to speak with their children about how dangerous these types of challenges can be.