"Someone came into my home. While we were sleeping. And removed nothing except thousands of dollars of LEGO. Small, rattly pieces of plastic," he wrote. "Either with a crew that should be large enough to be noticed, or with many trips up and down the stairs."
Richards said his family was home all day and the house remained locked from the time he went to sleep until he awoke the next morning.
He also added the thieves ignored his expensive electronics, camera equipment and tools while solely targeting his Lego collection.
"It sure sounds like a prank. A very ill-conceived and poorly timed prank," he said. "That's the explanation that makes the most sense of this situation. But nobody has stepped forward or returned anything."
Richard began amassing the $7,000 collection when he was 5 years old and has sought the help of law enforcement to return his beloved Lego sets.
"It's upsetting that they stole something that I've been building over the course of years," he told WXMI.
Grandville police are investigating the case and Richards has provided a list of the missing items on his blog.
He has asked law enforcement and other residents to monitor sites such as Craigslist and eBay for large amounts of Lego bricks or items from his collection being sold.