Driver's power seat will Move back-and-forth and the interior lights will come on?

Hello, I just bought this vehicle not too long ago and I noticed that it is having some electrical issues. Sometimes while driving or just randomly the driver's power seat will move back-and-forth, and the interior lights will come on for a little bit.

It looks like the previous owner installed a heavier duty hitch along with aftermarket wiring for it. I think they may have even messed with the fuse box and put in higher rating fuses than What is recommended. I can’t check it because the information is in the manual, and the vehicle did not come with a manual.

Besides, checking the fuses, what would be your avenue of diagnosis? Thank you so much for your help.