I purchased a house built in the 1920's for my office, its located in an area where many professionals have purchased and turned these great old homes into offices. I also own a vacation rental built in 1880 and another in 1905. This is what I look for.
1. Copper wire, replacing the old steel wire with insulators.
2. New panel with at least 200 amp service
3. Pex, plastic or copper pipe. Iron pipe and galvanized should have been replaced
4. AC fitted to the house with ducts rather than window AC units.
5. Modern water heater, preferably natural gas if available (insta hot units are good)
6. Original windows are ok (mine are original) as long as there is weather stripping
7. Check the floor for elevated homes, look for wood rot
8. Make sure the sewer system is free of tree roots
9. Check the foundation for cracks that are serious
10. Basements should have been remediated for Radon and moisture
Other than the above, go for it. For STR, people love the character of those old homes. You can have modern fixtures and electrical without destroying the original character.