Most microwaves don’t leak enough to be noticeable. You can buy a tester for a few dollars; it’ll just be a small bulb that glows (fluoresces) in the presence o

Most microwaves don’t leak enough to be noticeable. You can buy a tester for a few dollars; it’ll just be a small bulb that glows (fluoresces) in the presence of microwaves. Digital meters that can measure the exact strength of the microwaves also exist, though they are more expensive.