ALEXANDRIA, VA — (CNN) This is the story of a little PO box in Northern Virginia and the conspiracy that wasn’t.

When the Republican presidential primary was still in full swing in March, officials from Donald Trump’s campaign promoted a conspiracy theory — one of many — insisting there was a nefarious link between his political opponents and an anti-Trump super PAC.

It began this spring when a group called Make America Awesome, an anti-Trump group, posted a photo of Trump’s wife, Melania, that criticized her for posing semi-nude in a magazine photo shoot.

Trump responded by crudely lambasting the physical appearance of Ted Cruz’s wife, Heidi, and he justified it by claiming that Cruz was behind the attack on his own wife.

As evidence, Trump’s team pointed to a large donation that Carly Fiorina’s super PAC received from a pro-Cruz super PAC. And Fiorina’s super PAC, they noted, had the same mailing address as Make America Awesome, the group that had attacked Trump’s wife. Because those groups listed the same address, they claimed it was proof that the anti-Trump forces were operating from the same source.

Trump’s supporters, including his campaign’s social media director, Daniel Scavino, lit up the Internet with screenshots showing the identical address: PO BOX 26141 in Alexandria, Virginia.

Trump-friendly websites wrote about it as though it was evidence of a vast conspiracy against the Republican frontrunner.

CNN traced the address to a PO Box owned by Christopher Marston, an attorney who specializes in campaign finance compliance. It turns out that same address serves as the official “address” of dozens of campaigns.

So why would several groups all have the same address? The answer is not nearly as titillating: Marston’s business, Election CFO, contracts with dozens of campaigns and political action committees to provide services that including filling out their financial paperwork with the Federal Election Commission and handle accounting. It’s a common practice for political groups to contract out such work to experts trained in navigating the complicated campaign finance regulations.

“People just hire me to be their treasurer,” Marston told CNN in an interview at his home office in Alexandria. “I do accounting. Honest to goodness I really just write the checks and make the deposits.”

Despite his paper trail affiliation with campaigns and PACs, Marston’s role is almost exclusively clerical. His little PO Box isn’t the hub for GOP conspiracy meetings and he doesn’t involve himself with campaign strategy, messaging or opposition research.

“My interaction to those folks is mostly limited to paying their invoices,” he said.

There are many such companies who provide similar services for both Republicans and Democrats.

“It’s not a conspiracy,” Marston said.

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