There’s on and off construction on SR 33 exits and entrances all week. As of Thursday the SR 4 & 31 exit was open for SR 4 only allowing exit to get to the Union County Fairgrounds. If both 31 and 4 are closed, then continue NW on 33 another mile and exit at 36 (Kroger) and come back east on 36 to 4 and left (north).
An alternate is exit of Westbound SR 33 at the SR 36 exit (Texas road house, Chevy dealership) before the 31 & 4 exit and go west into town and right on 4.