You need to check also both Switch configurations (show config) in order to understand exactly if you have something related to SNMP configured in your Switches (I presume your Switches were both setup with Static IP addressing and they don't use - and offer - any DHCP service from/to LAN's hosts).
Interesting threads about your strange messages:
- snmp: SNMP Security access violation from 10.0.1.151 (read this).
- tftp: SENT error:1, msg: File not found (read this).
In both cases you probably have something running on a LAN host that is asking for access to your Switch (Access Violation error) and, concurrently, is trying to retrieve a file that don't exist in your Switch (File Not Found error).