'Trading Spaces' Host Carter Oosterhouse Sues -- You LIED to My Handsome Face!

HGTV star Carter Oosterhouse is really, really, ridiculously good-looking ... this according to Carter himself ... who just sued a flooring company for using his extremely pretty face without permission.

Oosterhouse -- who once hosted "Trading Spaces" -- is going to war with a company called World of Floors ... which sells flooring ... duh.

In the suit, filed in L.A. County Superior Court and obtained by TMZ, Oosterhouse claims, among other things, he signed a deal with WOF which ONLY gave them the right to exploit his mug for WOF ads featured in Michigan ... but the company used his image to market an affiliated national chain of furniture stores.

Big problem for Oosterhouse -- who describes himself in the suit as a "handsome and wildly popular TV personality." Mr. Modest also claims his image is extremely valuable.

In fact, his image is so valuable, Oosterhouse wants more than $500k from WOF and an ad agency that worked on the campaign.

TMZ spoke with Alan Sussman -- a rep for the ad agency -- who tells us, "The lawsuit is erroneous ... just like Mr. Oosterhouse's talent."

Fun Fact: Oosterhouse is married to Amy Smart ... and during a recent stop at LAX, he told us all about how they converted their home into a "green house." (below)