The ancient Roman household spirits Wikipedia compares brownies to are the Lares.
Brownies are helpful household spirits in Scottish and northern English folklore. Like the Roman Lares, they are associated with a particular home, domestic protection, the family hearth, and offerings of food or dairy. Both traditions connect household spirits with the continuing presence of the dead, especially deceased ancestors or former servants.
The comparison is not a claim that brownies descended directly from Roman religion. It is a folkloric analogy: both figures are solitary or household-bound helpers who serve residents in return for respect and offerings. Roman Lares were traditionally protective spirits of ancestors and households, while brownies were said to perform chores and farm work at night.
A common mix-up is with the Manes, another Roman category of ancestral spirits. The question asks for the specific comparison made in the brownie folklore article, and that comparison names the Lares.