is it true that this will mess with your wi-fi? will it cause any other problems with electrical wires in the walls?

Sugar rae - if you happen to have a picture of what you did, I would love to see it!

thanks for all of your help and I think I'd better be safe than sorry. what I don't understand is, why are all of the contractor's telling me I can cover the vent?

I want to cover it so I can get bigger cabinets. My kitchen is about 6x7 and it would be great to have more storage!