If you've got a big mold problem, first fix the source of it and then call in professionals to remediate it. Poor drainage, foundation or wall cracks, leaking roofs or plumbing, lack of sufficient ventilation or air-conditioning all contribute to the spread of damaging mold.
If you have visible mold in less than 10 continuous square feet, you may be able to remediate it yourself with dehumidification and a low-tech water trap attached to your vacuum to capture the spores.
The water trap can be made of any glass or jar. The one we use in the studio is in the image below. It is important to ensure that it is well sealed around the openings and the tubes. Ethafoam (a strong, resilient, medium-density, closed-cell, white polyethylene foam which is acceptable for use in the preservation of objects) is really helpful for this. Gwen even carved out a stand for the glass to ensure it would not fall over. The other critical aspect is the ends of the two tubes inside the glass are above the water line. It is the vacuum's suction that forces the mold spores into the water i.e. trap, while not traveling into the vacuum cleaner.
When finished, thoroughly clean all of the associated tools, mark them and save them together, including brushes.
It's very important to contain the spores, not spread them around (which is what regular vacuuming will do). Here's a step-by-step guide to what to do next and don't forget to wear an approved N95 respirator, gloves, and eye protection!
Gwen Spicer. When Water Strikes, It's a Freezer to the Rescue! March 2018.
Ibid. Mold on Pastel Portraits, why it grows and how it can be prevented. January 2017.
Idid. Mold in museum collections is the environmental "canary in a coal mine". September 2014.