Felicity and Bill are being sued by a woman named Lourdes Orozco ... who claims she went down hard on the stairway from hell back in April, 2011.
According to the lawsuit the stairs were "dirty and poorly maintained," and lacked "regulated handrails."
The suit further alleges WHM and his wife were negligent ... because they "knew or should have known" the stairway conditions "could easily cause anyone to slip and fall, as in [Orozco's] case, resulting in serious personal injury."
The lawsuit also accuses Macy and Huffman of willful failure to warn Orozco about the allegedly horrendous staircase.
It's unclear from the documents what Orozco's relationship is to Bill and Felicity. She's suing for damages in excess of $25,000 ... including lost wages and medical expenses.