The classic Simpsons example of this is in the X-Files episode somewhere. Homer sees a giant billboard which says “DIE”. He emits a cowardly shriek. The wind blows aside some foliage which had been covering part of the sign; it is now revealed to actually say “DIET”. Homer emits a second cowardly shriek.
Here in Cambridge, on Mass. Ave between Central and Kendall, there’s an old FIRE-PROOF STORAGE WAREHOUSE. If you look from the right vantage (near the train tracks) it appears to be an IRE-PROOF RAGE WAREHOUSE.
And the Boston Globe sidewalk boxes these days say “CATCH PLAYOFF FEVER”. Put the right tree in front of it, and you’ll see CATCH LAYOFF FEVER. Someone oughta make a campaign slogan out of that!