Is there anyway to catch mew on pokemon red (gameboy) after completing the game?

Ok there is a way but there are certain things you have must NOT done yet. Ok go to the side of Lavender Town. Go to that little house thing with the connector to whatever city town. SAVE! Now go out take one step down and press start to open the menu. If the old dude sees you turn off turn back on. Fly to that city where you fight Misty (i just haven'tt played it in a while sorry...) Go up Nugget Bridge and Go right where that huge mountain rock thing or whatever it is. Fight the youngster in front of the two bushes yeah the one with a slowpoke. Fly back to Lavender Town. Go to that route as if you were going back to the old dude you flew away from. The menu will open by itself, press the B button to cancel it out. The battle will start and catch yourself THE (not a) Mew!

P.S Don't do any of those lies like push the SS Anne truck, trust me they won't work.