In Lufkin, FM-58 is signed as US=-58 on the gantry signs on US-59
https://geo0.ggpht.com/cbk?cb_client=maps_sv.tactile&authuser=0&hl=en&gl=us&output=thumbnail&thumb=2&w=345&h=170&pitch=0&ll=31.31667667986432%2C-94.70619964284961&panoid=VSP-O6CNlGIQLwHzeLYOkQ&yaw=270
On Galveston island, SH-87 has some US-87 signs.
In texarkana there used to be signs on I-369 that refererence US-93 when the local road (Lake Drive) is SH-93. There may still be one, but most of them were removed.
I think the "Erroneous signs" thread would be a better place for these.
Here's the US/state Mix-up thread:
https://www.aaroads.com/forum/index.php?topic=18607.0
Original Erroneous Sign thread for other goofed signage (started out with similar errors):
https://www.aaroads.com/forum/index.php?topic=87.0