You fell in LOVE. At the local thrift store, garage sale, or (yes even here) antique store. Antique stores, especially high end stores, should take care of these things or at least warn you, but we are going to assume they do not, so you take care of you.
The cabinet (desk, chest of drawers, bed, whatever) was PERFECT, and you couldn’t wait to put it into that special place you’ve been trying to fill, and so you move it into your home.
WAIT! Check it out before you do! Take the drawers out . . . look around the inside of the frame. Hmmm . . . webs, dirt, spider eggs. Do you really want that in your home?
Put on gloves (not the elbow-length pink sparkly ones but sturdy spiders-can’t-bite-me ones) and if you have the type of vacuum that allows you to rinse the holding tank our after you toss the contents (like a Dyson), vacuum all the debris, dust and eggs.
Open cabinet doors and do the same, then turn the piece over and vacuum the underside. I usually start with a bare hose, then put the brush on after I have gotten the bulk of the dirt, debris and eggs. After, wash the inside of the vacuum and the brushes.
Inspect for mold, and for the signs of the piece having been through a water event — a watermark might be present, even if it was just the kitchen sink overflowing.
If you find mold, what you do next depends on the value of the piece, whether it is a fine antique, painted or other finish, or upholstered. For pieces that are not expensive, or pieces that have lost their finish or you are going to strip, make a 10% solution of bleach.
Wear plastic or non-permeable gloves, as some molds are deadly, and wear a surgical mask as well. Test the area you want to bleach and let it dry completely.
If there is no reaction to the bleach on the part you tested, then take a 1/2-inch wide craft brush and paint the areas with the bleach solution.
However, if the piece is a good piece, a delicate piece, has a nice finish, a decent old finish, is lacquered, or you are going to restore it, contact a conservator and have them at least take a look at the mold before you work with it. Conservators have many other ways to clean molds, and can tell you if the bleach solution is safe for the piece.