CLEVELAND -- A postal employee working his regular route came across something unusual Thursday. What had been left inside the mail drop box was smoking.

The bomb squad was called in to investigate and soon a HAZMAT team arrived.

"Somebody seen something in the mailbox thought it was a bomb, it was equipment to make drugs," said Samantha Traina, the sister of the woman who was arrested at the scene.

An officer at the scene told Channel 3 News that the bottles they pulled out were part of a mobile meth lab.

The discovery led them to a house about a block away where another HAZMAT search was underway.

A woman who we'll call "Lynn" says she lives above the unit where police were searching.

"That scares me because we're all so close together, if something would've blown up, we all would've been," said Lynn.

Traina doesn't know if her sister was behind the meth lab, but did say her sister is a drug addict, whose addiction put people at risk.

"You never know if the house is going to blow up or catch fire," said Traina.

After crews got a good look at whatever was inside of that downstairs unit, "Lynn" was told she may need to move.

It's a suggestion she's taking very seriously.

"I mean, I've lived here my whole life but maybe it's time I get my kids and go elsewhere," said Lynn.

The substances have been sampled and are currently being tested for further identification.