Oh, how the mighty Madoffs have fallen.

Fresh off getting booted from her huge Upper East Side penthouse, the wife of Ponzi-scheme king Bernard Madoff is eyeing a bland new apartment that’s tiny — very tiny — in comparison to their old digs.

Read More on Ruth Madoff in Gimme Shelter

Ruth’s real-estate broker recently took a look at a cozy little condo for sale in The Trafalgar House, a 15-story building at 120 E. 90th St., sources told The Post.

The only unit listed for sale there is a one-bedroom, one-bathroom that takes up just 481 square feet — 3,529 square feet less than her former four-bedroom duplex atop 133 E. 64th St., which federal authorities seized July 2.

The fixer-upper is in serious need of renovations. The hardwood floors are crying out to be refinished and repaired, the ceiling is missing large chunks of plaster, the walls are scuffed, the paint is peeling paint, and the cramped kitchen features orange linoleum on the floor and yellow Formica counters.

And the view from the window is mostly of the back of a neighboring building.

But on the bright side, the price is a lot less than the $7 million or more Ruth’s old apartment could fetch when it’s sold off by the government to help pay back some of the thousands of investors from whom her husband swindled $65 billion.

The Trafalgar apartment has an asking price of a mere $465,000. Taxes and common charges would total just $779 per month.

That’s certainly affordable for Ruth, 68, who was left with just $2.5 million after cutting a deal with the feds to surrender all her other assets just before Bernie, 71, was sentenced to 150 years in prison.

“All that’s needed is a little TLC to transform the apartment into a lovely living space,” says the Web site of the listing company, Trump Sales and Leasing.

Trafalgar residents were less than enthusiastic after hearing Ruth may be moving in.

“Oh, my God, that would be so horrible,” one resident was overheard saying. “We don’t want that tension in here.”

Although she apparently will not be prosecuted in connection with her hubby’s heinous fraud, Ruth has become a pariah since Bernard’s arrest.

In recent weeks, a number of Upper East Side buildings have refused to accept her as a resident, given her notoriety.

And on June 30 — two days before she vacated her penthouse — US Marshals seized her $3 million Montauk, LI, house as part of her asset-forfeiture agreement.

Ruth’s lawyer, Peter Chavkin, scoffed when asked about her interest in buying an apartment in The Trafalgar.

“Given her economic circumstances, it’s completely ridiculous to even suggest that she would be looking to buy something,” he said.

dan.mangan@nypost.com