https://fas.org/sgp/crs/misc/R45769.pdf
Note the last sentence:
Impeachment proceedings are usually initiated in the House when a Member submits a resolution through the hopper (in the same way that all House resolutions are submitted). A resolution calling for the impeachment of an officer will be referred to the Judiciary Committee; a resolution simply authorizing an investigation of an officer will be referred to the Rules Committee. In either case, the committee could then report a privileged resolution authorizing the investigation. In the past, House committees, under their general investigatory authority, have sometimes sought information and researched charges against officers prior to the adoption of a resolution to authorize an impeachment investigation.