Blue liquid leaking in corners and the inside vent of over range microwave.

Your microwave oven is long overdue for replacement.

Could be silicon based.
Best thing is to not use the microwave till you contact the manufacturer to see if it is toxic or a repair needed.
If it is an old model get a new one.
Here are some old converations
there is blue liquid comes out from the joint inside microwave what is...

its the high tension fuse .9 size its long

Ebola would be my first guess. Is the cat missing?

There are capacitors inside that could leak, could be that also.

take the screws out of vent and remove to clean inside the inter vent

Without a long explanation as to why but they will get a build up. At this juncture i would be prudent to just clean it well. Because it will require you to remove the outer cover, you must disconnect it. Be careful when you do this, no metal objects. It has parts that store electric. Once you open it you will see the build-up. Do not open the metal box, it is the part that stores the electric.

unless something strange happened (like a spill) then the only component that has fluid in it is a large capacitor that is used to drive the magnetron ... if its case is ruptured then it will leak a few teaspoons of electrolyte .. thats a clear water or oil based liquid .. the failure of the aluminum case will cause a pop one time ... then its likelly the oven will quit working .. its also possible, if you have an outside vent for your microwave, that water is blowing into that vent down into the microwave .. check the exhaust to make sure its outside louvers are not damaged ..if it goes to the roof then make sure the rain cap is in place ..

Have you selected a microwave yet?

many over the range types can be vented inside if a charcoal filter is used, which you must replace about every six months.

Otherwise, you will need to install a vent system in the kirtchen.

i had the same trouble, yes i used a solid bolt to hold the microwave bracket in the stud then used the biggest toggle bolts that will fit, also the cabinet will not have to be changed. it works fine, if you had a vent a hood dont forget to hook up the exhaust vent. i figure your old exhaust vent is in the cabinet like mine was

"Microhood" seems to be a slang term for the "microwave hood" (hood fan or exhaust fan) which is normally part of an over-the-range microwave oven or range. But these should be available separately, as I seem to recall. I would contact home centers such as Lowe's, Home Depot (if they still exist), etc., or a local appliance store.