gistfile1.txt

// How to use
[StringToEnum("None", "Road", "House", "Water")]
public string menuEntry;

StringToEnumAttribute.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[System.AttributeUsage(System.AttributeTargets.Field)]
public class StringToEnumAttribute : PropertyAttribute
{
    public string[] values;

    public StringToEnumAttribute(params string[] values)
    {
        this.values = values;
    }
}

StringToEnumDrawer.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;

[CustomPropertyDrawer(typeof(StringToEnumAttribute))]
public class StringToEnumDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {

        if (!(attribute is StringToEnumAttribute att)) return;

        var index = System.Array.IndexOf(att.values, property.stringValue);
        if (index < 0) index = 0;

        EditorGUI.BeginChangeCheck();
        index = EditorGUI.Popup(position, property.displayName, index, att.values);

        if (EditorGUI.EndChangeCheck())
            property.stringValue = att.values[index];

    }
}