Here are random data sets I've generated for parapsychology/psi experiments. All are plain ASCII text and have passed the NIST and Dieharder tests for randomness.

Random Geiger counter data captured from a GMC 300+ Geiger counter. Each number inside the files (0,1,2,3, etc.) is the number of random radioactive particles detected since the meter's last check. Checks were performed every few seconds:

     geiger1.txt (12KB)
     geiger2.txt (15KB)
     geiger3.txt (15KB)
     geiger4.txt (12KB)
     geiger5.txt (30KB)
 
     All data above XOR'd together as binary (geiger_xor.txt, 13KB)
 
     NIST/Dieharder Randomness Test Results (6KB)
 

Random binary data from circuitry thermal noise captured from Assembly Language calls to the RDSEED function in an Intel i7-10510U CPU:

     rdseed.txt (15KB)
 
     NIST/Dieharder Randomness Test Results (6KB)
 
     If you want even more, here's 1MB of RDSEED random binary data: rdseed_1M.zip (142KB). It might come in handy for a top secret One Time Pad (OTP).