University Communications is the point of contact for photography at CMU. You will find information about what is available through this office at:
There is a collection of photographic images for sale at the CMU Photo Store:
For pubic images of CMU, you may want to search Google Images (https://images.google.com) for "central michigan university". You can click on the TOOLS button to filter the results by license. Those labeled for reuse should have conditions for reuse on the web page for the source.